Luis Castillo Sent to White Sox, M’s Get Middling Package: 2026 Trade Deadline Analysis Part I
The 2026 trade deadline has come and gone, and while the team sealed a Monday deal to bring righty stick Taylor Ward onboard as a rental, the bigger long-term move was on Saturday.
“The Rock” is no more. Well, at least in the Mariners clubhouse; not only is Dwayne Johnson still wrasslin’, but Luis Castillo is still playing baseball - just with the Chicago White Sox.
Seattle entered the trade deadline with six starting pitchers and two near-MLB ready hurling prospects tearing up Double-A more thoroughly than the family cocker spaniel handles little Timmy’s (previously completed, I’m sure) homework. The most obvious candidate for offload was Castillo, who has a 5.06 ERA, 4.57 FIP, and 1.395 WHIP over 20 games and 17 starts this season, not to mention around $30.3 million (the $7.178 million in prorated contract from this year and the $24.15 million for next year) in remaining guaranteed money until the end of 2027.
The team was in talks, evidently, about fellow starters George Kirby and Emerson Hancock, but with a standard five-man rotation after sending Castillo to Chicago’s South Side, there is a clear order of who’s going to pitch in these next few weeks.
The Sox sent the Mariners three players in return: right-handed relief pitcher Seranthony Domínguez, 28-year-old outfield project Nolan Jones, and Double-A catching prospect Boston Smith. Chicago also sent an undetermined amount of cash to the Mariners as part of the trade.
As for Castillo, while this perhaps isn’t the return the Mariners might have been hoping for (many mocks had been made about some sort of big MLB-impact return from the pitching-starved Cubs, for example), it makes sense that Castillo didn’t net a bat. His first year with the Mariners at age 29 was similar to his peak seasons with the Reds, but after that, his production began to decline year-over-year. The following chart from FanGraphs shows ERA, fielding independent pitching (FIP) and expected FIP (xFIP) in each of his big league seasons:
Five Mariners Homers Overcome Heavy-Hitting Dodgers in Chavez Ravine Thriller
The Mariners’ disastrous series against the Rangers finally put to rest the notion of the team as the AL West favorite, with a 52-55 record and a two and a half game deficit in the division with a month-long gauntlet fast approaching. What had been true for the whole season was now eminently evident to the entirety of the dugout: that both greater commitment and greater precision are needed in order to return to the playoffs, much less to the precipice of the pennant.
Iron, as they say, sharpens iron; who better to face than the two-time defending champion Dodgers? They immediately displayed why their offense is one of the best in baseball, working to quickly punish whatever Luis Castillo pitches leaked out over the plate. But the Mariners, needing a win to keep pace with the Rangers and Astros ahead of them, managed to put together a thrilling 7-6 victory on the backs of five home runs and some high-stress relief pitching.
It was the first Mariners win against the Dodgers since April 19, 2021. It was the first Mariners win in Dodger Stadium since June 28, 2009. To put it another way: the last time the M’s beat the Dodgers in the City of Angels, Rob Refsnyder was 18, Cal Raleigh was 12, Dominic Canzone was 11, and Julio Rodríguez was eight. Those were the four M’s to go deep on Tuesday.
Cal Raleigh and Julio Rodriguez hit a homer in the same game for the first time since April.
Before the season began, the duo of Rodríguez and Raleigh were projected to accrue between five and six wins above replacement (WAR) each. With 55 games left in the season, Rodríguez had 1.8 FanGraphs WAR (fWAR) and Raleigh 0.5, each reflective of injury-shortened years with significant struggles - especially in the case of Raleigh, who had a .165/.269/.300 slash line going into Tuesday.
The struggling catcher found himself on the IL for roughly a month-long stretch of time straddling May and June, but he appeared set to roar back on the scene after a homer-studded rehab assignment in Tacoma. That ended up being a mirage; Raleigh had a .170/.304/.277 slash line between his return on June 16 and the end of the Rangers series on July 27. The power stroke was especially absent, as he had just three homers during these 33 games.
Three Burning Questions for Mariners at All-Star Break
The Seattle Mariners, along with the rest of MLB, have completed the unofficial "first half" of the 2026 season. The baseball world focuses on Philadelphia over the next few days as the All-Star festivities begin in the City of Brotherly Love. The Mariners enter the break one game below .500 at 48-49. It certainly has been a frustrating, uneven first half of a season where the team, and its fans, felt a berth to the franchise's first ever World Series was at hand.
Nothing in this beautiful, amazing, dumb sport is that simple. Now, the Mariners have serious questions. Ones that need addressing if the Mariners are to even make the playoffs at all, much less punch their ticket to the Fall Classic.
Are Cal Raleigh and Josh Naylor ever going to snap out of it?
The fact that the Mariners are in a playoff spot (tied for last Wild Card spot) despite getting virtually nothing from Raleigh and Naylor is a minor miracle. They are batting a combined .218 with just 17 homers combined. For reference, these two sluggers had - you might want to sit down for this - 49 home runs before the All-Star break. After Naylor arrived at the deadline last season, he was an instant spark and the deal he signed to stay in Seattle long term seemed like a no-brainer.
Mariners Drop Fourth Straight as Randy Arozarena Mishap Causes Tension
The Mariners are back under .500, with a 47-48 record nearly 60% of the way through the year, reeling from their fourth straight loss in Florida on Friday, this time by a score of 7-2. With the result, the Rays have won 12 of their last 16, while the M’s have lost 10 of their last 16.
The first inning was something of a microcosm of the way these two teams entered the game, one with tons of fight and firepower and the other limping along. The final line from that frame of zero runs for either team was reached two starkly different ways: from the Mariners, it was three ground ball outs, but for the Rays, it was a double, a walk, and an infield single to create a pickle for Mariners starter Luis Castillo.
Its greatest and most obvious microcosm was the defense. J.P. Crawford, on the first pitch of the game, dribbled a ball up the middle that Rays second baseman Richie Palacios snared on a falling run. Meanwhile, in the bottom half, the selfsame Crawford was unable to make a play on a ground ball hit directly his way and created the aforementioned infield single.
The obvious example of completely preventable defensive damage was when Randy Arozarena slowed to a trot on a fifth inning foul ball that was extremely catchable, after which Rays hitter Cedric Mullins cracked a home run to put the Rays up 3-1. That moment had infinitely more impact on the course of the game than what I’m about to describe - and caused plenty of tension between Arozarena and starter Luis Castillo - but there was another moment that summed up the energy (or lack thereof) among the Mariners.
What Would a ‘Buyer-to-Buyer’ Trade for Mariners Look Like?
It’s almost the All-Star break. That means it’s trade rumors season. It’s an exciting time for all 30 MLB teams. If your team is in contention, excitement builds about which players your team’s general manager might acquire from another team. Fans enjoy conjecturing trade packages that would benefit their team.
Even if your favorite team is seemingly out of the race (although with now three Wild Card spots, that pool of teams is smaller than ever), there are still reasons to tune in. Die hard fans of teams not in contention start stalking the prospects of other MLB organizations, guessing which teams might trade for their best big leaguers to merit exciting young talent in return.
This season is a bit unique. The American League, as a whole, has been very mediocre. Only one team in the entire AL (Angels) is double-digit games back of a playoff spot. Even the 38-54 Royals are 8.5 games back of the last AL Wild Card spot. This leaves the August 3 trade deadline in a weird spot.
That led to Seattle Mariners president of baseball operations Jerry Dipoto having an interesting quote on MLB Network Radio, saying, “I think there are enough contending teams with real holes or needs to fill that you might actually see more action with contender trading with contender like, buyer-to-buyer type trades to fill voids.”
Analysis: Why Seiya Suzuki Could Be Missing Piece for Mariners
After coming up a few innings short of making the fall classic last October, the Seattle Mariners came into the season as one of the favorites to represent the American League in the World Series. Yet, even after winning five of its past six games, Seattle sits hovering just above the .500 mark.
Injuries and inconsistency have been the main culprits for not being able to pull away just yet in a pedestrian AL West division, but the inability to hit lefties has proven to be the M’s Achilles’ heel. During the offseason, the team added outfielder Rob Refsynder with the hopes he would help in that department, but he has been abysmal all season and recently landed on the disabled list with a knee injury, creating even more questions against southpaws.
Some improvement needs to come from current star players such as Cal Raleigh and Julio Rodriguez on this front, but outside additions are needed for a second half surge and a shot to get to the World Series for the first time. Of all the realistic options potentially out there, one stands out as a win/win for both teams with the pitcher-needy Cubs and outfielder Seiya Suzuki, who would be the ideal deadline addition for the M’s for a variety of reasons.
Four Runs Still Out of Reach as Mariners Fall 4-3 to Guardians
The Seattle Mariners continue to eye franchise history - for the wrong reasons - as they tied the team record with 13 games in a row while scoring three or fewer runs in a 4-3 loss to the Cleveland Guardians on Saturday. Holding onto a half-game lead in the middling American League West, the Mariners need to decide if they want to build on last year's success or drift sheepishly back into mediocrity.
Even the most optimistic Seattle fans know the phrase “Same old Mariners.” It encompasses the feelings of a downtrodden fanbase that has only made the playoffs six times in their 50 years of existence. Despite having the greatest season in team history last year by reaching Game 7 of the American League Championship Series, most fans are already ready to chalk it up as a fluke given their team’s struggles this year.
The roster is not devoid of talent; quite the opposite actually. FanGraphs Playoff Odds still gives the M’s an 80.3% chance of making the postseason. The lineup still needs to wake up though, as this roster has shown that it cannot sleepwalk its way to winning the division.
The trade deadline is approaching. Changes need to be made. What can this SoDo squad do to get back on track?
Mariners Pitchers Lock Down Win Despite Continued Batting Sluggishness
A bobble from Guardians second baseman Travis Bazzana in the top of the seventh seemed like the first piece of good luck the Mariners had gotten in a very long time. It came with two outs and a man on third, turning what would have been an inning-ending grounder into a go-ahead run for the Mariners. It proved the winning run in Seattle’s 3-1 victory against Cleveland.
On the one hand, none of their issues really fixed themselves. The team couldn’t get a fourth run for the 12th straight game, marking just the third such streak in team history. Pitch recognition woes and issues against left-handers continued with no real end in sight. But on the other hand, for the fifth time in those dozen games, it was enough.
Luis Castillo tossed a quality start, with all his pitches in action.
Mariners starter Luis Castillo came into the game with a better track record since the onset of his first piggyback outing, but there had still been notable inconsistencies for him. Despite a 3.38 ERA in his six appearances since the first piggyback, he was still without a quality start aside from his first outing of the year. Going into a game where the M’s did nothing but continue to crawl along on offense, he needed to find his best stuff for a full start.
Luckily for the M’s, Castillo had a firm command of all three of the pitches he needs to build a good outing. The slider was his most common delivery, followed by the four-seamer and changeup in that order, but he threw each quite often with the occasional sinker thrown in.
Mariners No-Hit Through 6, Late Comeback Comes Up Short in 6-2 Loss to Red Sox
Coming off a gratifying shutout victory against the Baltimore Orioles, the momentum slowed down for the Seattle Mariners on Friday night. Facing an underperforming Red Sox team limping into the Emerald City, Seattle looked primed to rattle off a win streak against a Boston squad fresh off suffering a sweep by the Toronto Blue Jays.
Boston had other plans however, capitalizing on poor pitching decisions, an inability to hit lefties, and a lack of bench depth, as the Sox punished the M’s mistakes at every turn to open the series with a 6-2 win at T-Mobile Park.
Julio Rodriguez homered in the ninth inning to drive in two runs, but it proved far too little, too late. Outside of the centerfielder’s blast, the Mariners had little to celebrate on Juneteenth as they donned their popular Steelhead jerseys, paying homage to the Negro League team that predates the M’s.
What went wrong in the Mariners’ latest defeat?
Mariners’ Tuesday Bombshells: Rotating Piggyback, Pereda Sent Down, Arozarena to IL
Tuesday ended in a solid 3-1 win for the Mariners at home against the Orioles, but a flurry of roster moves and decisions may have been even more hectic for the team than that night’s action. The team called Cal Raleigh back up to the MLB roster, announced a first-of-its-kind rotating piggyback, and had to call up a guy who had taken four total plate appearances above High-A ball in his entire career thanks to a seemingly bizarre lack of preparation on Randy Arozarena’s injury status.
Mariners general manager Justin Hollander, speaking with media Tuesday afternoon, noted the inordinate severity of the injury situation as compared to other bugs he had dealt with in his tenure with the team; he noted that Luke Raley and Josh Naylor were both dealing with issues and that Matt Brash, Carlos Vargas, and Cooper Criswell would be out until around the trade deadline. Brendan Donovan is set to start running work in the week, but these persistent injuries are not a good sign. This is especially true of Raley’s lower back tightness, given that similar injuries ended up shattering his 2025 season well after he was officially healed.
The mechanistic plan to have each of Seattle’s six starting pitchers rotate the piggyback amongst themselves is many things, but to use a judgmentally neutral term, it is unprecedented. It is also seemingly contradictory that the same organization that came up with a plan as intricate as a rotating piggyback also waited until a gameday to MRI Arozarena despite having a rest day to do so; had they done the simple thing of scheduling an earlier MRI, they would have been able to call Connor Joe back up as is clearly their long-term plan.
But what’s done is done, as bizarre as the events were. What should be made of these decisions, and what do they mean for the near future of the Mariners’ season?
Mariners Forget Fundamentals, Drop Saturday Game 8-3 to Nationals
It seems the Mariners are yet to escape their consistent inconsistency. After having beaten the Washington Nationals 10-2 the previous day, with every starting Mariner position player getting a knock, the team lost 8-2 as the pitching slipped up and the offense took a big step back outside of the ever-impressive Colt Emerson.
But the biggest issue for the team was the defense, which was docked for three errors and looked quite shaky even outside of those official events on the scoresheet. The game served as an example of bad fundamental play across the board and a reason why the team has a losing record in one-run games and just one win after trailing in the seventh. They still have the luxury of playing in the division that they do, but they aren’t forming good habits for the playoffs and the lack of precision has turned what should be a lock in the weakest division in baseball into a 1 ½ game lead over a mediocre Athletics team.
Defensive miscues piled up early, and a would-be clean first became a three-spot for the Nats.
Josh Naylor didn’t have himself a very good game on Saturday, with big misses with the glove and stick. The former came first, with a bad throw in the bottom of the first allowing the Nationals to put together a two-out rally and tack three runs on Luis Castillo.
Winning Fixes Everything: Mariners Enter June in Excellent Shape
Rarely does a 2 ½ game lead seem so wide. Yet with the way the Mariners are playing and the roster they have, there is a very real possibility that the third month of the season cements them as clear AL West leaders. They do, after all, play in the game’s weakest division this year.
FanGraphs’ projections are often seen as the gold standard for playoff chances, often given without comparison as the stone cold definitive odds. According to FanGraphs’ default projections, the M’s have a 67.7% chance to win the division.
Baseball Prospectus’ PECOTA has been even more bullish on the M’s from the jump, and their current figure is 78.9%. Even models that weight games played more heavily than preseason projections have the M’s at a greater than 50/50 chance to keep the crown: Neil Paine’s Elo model gives Seattle a 57.7% chance to win the West while FanGraphs’ season-to-date projections give the M’s a 56.3% chance.
But the thing about streaks is that they end. After all, this is a game where a team can throw eight no-hit innings and lose 13-8. Where do the M’s need to see improvement in June, and what has to happen to keep their hot players going?
Analysis: Why Continue Piggyback When Tactic Lacks Intended Benefit?
From the score of the game itself, the Mariners’ performance on Monday against the A’s was as good as they could hope for. Seattle took advantage of some defensive miscues in the top of the third to scratch across a pair of runs before the wheels flew off Sacramento starter Aaron Civale’s bus with two outs and the team wound up with a 6-0 lead before the end of the frame and a 9-2 win by the end of the game.
But that explosion of runs papered over some clear tension as the team continued to use its tactic of piggybacking two of their six starters. To be abundantly clear, the tension itself isn’t the main reason why the idea is flawed - that would be the self-imposed constraints on player usage - but given that it seems to have been adopted in order for such tension to be avoided, the uneasiness was notable and instructive.
Bryce Miller had spun a gem given his pitch limitations on Tuesday, May 19, going 5 ⅔ innings in the first of Seattle’s attempted piggybacked starts. The game fell apart in the ninth as the M’s tried to stretch the piggyback beyond the point where it made sense, but Miller’s performance itself during that game was a good sign.
Mariners Win Series in Houston, Set Sail for Uncharted Waters with Raleigh Out
After their 8-3 victory against the Astros on Thursday, the Mariners are 7-1 with a +26 run differential against that team in 2026. They’re also 15-22 with a -7 run differential against every other team.
Thursday was something of a fulcrum for Seattle. It was the day the M’s officially sent Cal Raleigh to the 10-day IL, though this was an obvious development after his exit from Wednesday’s game with clear discomfort on the same oblique he had tweaked earlier. Mitch Garver caught Luis Castillo in the latter’s final full start for some time as the piggyback plan goes into effect the next time through the rotation. The cloud of these changes hung over the game’s activities, which saw the M’s take the bad Astros pitchers to task once more.
Brendan Donovan and Mitch Garver stood out on both sides of the ball on the day Cal Raleigh went to the IL.
There were two individual performances in particular that echoed Raleigh’s absence in a way. Garver, obviously, moved into the primary catching role upon his addition to the IL, while for Brendan Donovan, his performance was a lesson in the virtues of caution around early injuries.
Bumpy Stretch For Rotation Blocking Mariners’ Breakthrough
One of the clear strengths of the Seattle Mariners at the beginning of the 2026 season was their starting rotation. Last season, they ranked fourth in Major League Baseball in innings pitched as a starting rotation and 11th in FIP (which is ERA but factoring out fielding luck).
Bryan Woo and Luis Castillo eclipsed 180 innings pitched. Two of their starters had an ERA better than 3.50. Three of them exceeded 160 strikeouts. Four of their starters made at least 23 starts last season. Eight different players needed to make at least two starts. For context, the World Series champion Dodgers had 14 different players make multiple starts. The American League champion Blue Jays needed 11 such starters.
They had one of the strongest, most reliable rotations in baseball last year. With the same cast of characters coming into 2026, the consensus was the Mariners would be able to lean on their starting pitchers to another postseason run. However, over the last few weeks, the starting pitching has not been the strength, but the weakness of this Mariners club.
Another “Rock” Detonation Raises Rotation Questions for Mariners
In Luis Castillo’s first start of the season, he blew down the New York Yankees with basically two pitches: his four-seamer and slider.
Over the following five outings, Castillo has given up less than four runs just once and has not finished a single sixth inning. Over that time, he has given up 35 hits, 24 runs, and 20 earned runs in 22 ⅓ innings, an 8.06 ERA over that time.
Five of those innings came on Monday night in rainy Minnesota. Although in his previous four starts (also struggles of outings, though not without bad defense behind him), he had struck out 16 and issued seven walks while giving up two homers - it was all hits in the field that had sunk him - Monday’s game was bad in the so-called three true outcomes and bad in the actual result. Castillo gave up two home runs, walked two batters, and struck out three. He gave up seven hits in total and just as many runs.
The Mariners’ loss on Monday started and ended, mostly, with Castillo’s bad start. Sure, debutant Alex Hoppe’s second inning of work fell off the rails as his control waned and hitters adjusted to his slider, but the M’s had essentially decided on pushing Hoppe as far as they could to mop up the game. Sure, the Mariners offense took quite a while to wake up, but they managed to put four runs on the board.
The question has to be raised: does Castillo’s slump warrant a change in outlook for the Mariners about how to utilize him for the rest of the season?
Still-Sleepy Mariners Suffer Sixth Loss in Eight Games, Lose Series to Athletics
SEATTLE, Wash. - The M’s didn’t look much worse on Tuesday night than they had all year. The problem was that they didn’t look any better, either.
All they have shown in the first 25 games of the season has been mediocrity, inconsistency, and a gradually weakening confidence in their own abilities. The team hasn’t fallen fully off the table, but as the drudgery continues seemingly indefinitely, the phrase “right now” will become an ever more faded addendum to the phrase “this team is bad.”
Because let’s be realistic: the M’s can’t bank on a 10-plus game win streak to propel them out of the herd every year at the last moment; at some point, they need to learn how to start the regular season strong and not let up. Lifeless 5-2 losses to a sneakily threatening divisional rival can only happen so often for a team with World Series aspirations.
Luis Castillo threw a decent outing, but a high pitch count and loss of secondary control late forced him out early.
For an organization used to unearned no-decisions, Luis Castillo’s five innings of two run ball was about the platonic ideal of a no-decision.
Crawford Completes Comeback with Walk-Off Single, Mariners Best Astros 8-7
“J.P.! J.P.! J.P.!” rang out the chorus of 43,294 happy, exhausted spectators on Saturday night. Perhaps some of the Central Washington students among them (who had a special discount for the game and got some CWU-themed jerseys) were planning on continuing the night on Lower Queen Anne or Capitol Hill; the older and wiser CWU alums in the crowd were probably set to take their modes of transportation home so as to get some shuteye. All of them shared in the electricity of the evening’s end.
Mariners shortstop J.P. Crawford hadn’t been part of much of the first two weeks of the season for Seattle, nursing a shoulder injury sustained in Spring Training, and the first five games of his season saw him hit a paltry .118 over 26 plate appearances.
“I was going crazy not being able to play,” Crawford told Mariners TV’s Ryan Rowland-Smith after the game.
The Mariners shortstop had put together a 1-3 game with two walks during Seattle’s skid-breaking win on Friday, hitting leadoff with Brendan Donovan out of the lineup with an illness. But Saturday night saw him punch through a pair of massive bases-loaded singles to bookend the team’s biggest comeback of the young year.
Mariners Waste Lucky Breaks that Angels Take, Drop Series with 8-7 Loss in Extras
There’s always a strange air around games between the Angels and Mariners. Any divisional rivalry series will have an edge to it, but for the Halos and M’s, it just feels a bit different.
It probably has something to do with this: the modern Perry Minasian Angels are a mirror of the Jack Zduriencik-era Mariners: both teams stuck in the doldrums of mediocrity, wasting the career of two generational players (one Japanese superstar each), but each doing it in the opposite way.
Where the 2010s M’s caromed between 95-loss disasters and missing the playoffs by a game or two, the 2020s Angels hover around 70-75 wins year-in and year-out. The Zduriencik Mariners failed to shore up generational pitcher Felix Hernández, while the Minasian Angels have left future Hall of Fame center fielder Mike Trout out to dry. Ichiro was the first Japanese position player to light up the MLB (doing so with an old-school Wee Willie Keeler-style approach), but was nearing the last few years of his career by the time Zduriencik sent him to the Yankees. Shohei Ohtani, a much more homer-focused modern great (who, by the way, can also pitch) was a few years into his pro career before going to Anaheim.
Cal Raleigh Walks Off Yankees, Mariners Take One-Run Win Despite Missed Chances
The Mariners exited the weekend four-game set against the Guardians having scored nine more runs than their opponents but with just as many losses as wins. One-run games on Thursday and Saturday both went against the hosts, with the team seemingly figuring out how to deploy its roster in close matchups.
Seattle faced another one-run game against a 3-0 Yankees team on Monday night, and although the pitching was filthy, both the defense and offense seemed to have a bad case of the Mondays, letting several opportunities slip past at the dish and serving up a key non-out to New York in the seventh. But all’s well that ends well, and none other than Cal Raleigh knocked the winning run home in the bottom of the ninth to put all the night’s adversity behind them.
Luis Castillo notches his 1500th strikeout against Aaron Judge to cap off six shutout innings.
Mariners starter Luis Castillo isn’t the ace he once was. His once-elite grounder rate from his time with the Reds fell to around league average in his last few years with the Mariners, and his above average ratio of homers to fly balls in 2025 suggested he got on the good side of the Seattle marine layer. Still, his decline into his 30s has thus far been a graceful one, with a 3.54 ERA and 3.88 FIP last year.
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