Mariners vs. Athletics: Opening Weekend Series Preview
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Seattle Mariners pitcher Logan Gilbert fires a pitch during a regular season game at T-Mobile Park. Credit: Logan Gilbert/Instagram [/caption]
Happy Opening Day! Tonight at T-Mobile Park, the Mariners will be kicking off the 2025 regular season with the first of four games against the division-rival Athletics. Seattle won the season series 9-4 in 2024, but the A’s, embarking on their first season after abandoning Oakland, are an improved and exciting young group coming off a 32-32 second half and a busy offseason.
Let’s go over what the pitching matchups have in store.
Game 1: RHP Logan Gilbert vs. RHP Luis Severino
Gilbert gets the ball for the first Opening Day start of his young career. The former first-round pick out of Stetson established himself as the ace of the Mariners’ staff in 2024, spinning a 3.23 ERA (3.27 FIP) while averaging a little over a strikeout per inning over the span of a league-leading 208.2 innings pitched. The A’s slashed just .154/.167/.308 in three games (18.2 innings) against Gilbert a year ago, scoring six runs — five earned — on 10 hits with 21 strikeouts and just one walk, and the offense remains relatively unchanged aside from the minor arrivals of third baseman Gio Urshela and former Mariner Luis Urías, as well as the expected debut of infield prospect Max Muncy. Gilbert has especially handled All-Star slugger Brent Rooker well, giving up just one hit in 13 at-bats while striking him out seven times.
On the other side, Severino will make his A’s debut Thursday night after signing a three-year, $67 million deal with the club this winter. Poor performance and a late-season oblique injury in 2023 temporarily sidetracked his career — and ended his near decade-long tenure with the Yankees — but a resurgent 2024 campaign with the Mets, in which he posted a 3.91 ERA (4.21 FIP) over 182 innings, was good enough to land him atop the A’s rotation. You don’t have to look that far back to find the last time the Mariners faced Severino at T-Mobile Park; it was on August 11, 2024, when Seattle tagged the righty for four runs on six hits, including home runs from Jorge Polanco and Cal Raleigh, on its way to a 12-1 win over New York on Sunday Night Baseball.
Game 2: RHP Luis Castillo vs. LHP Jeffrey Springs
After a regressive 2024 season, Castillo’s name cropped up in trade rumors aplenty over the course of the winter. But in Seattle he remains, and although his two-year run as the Mariners’ Opening Day starter has come to a close, he won’t have to wait long for his turn to take the mound. Despite the down year by his standards, as well as the minor hamstring injury that abruptly brought his season to an end, Castillo was still worth 2.3 fWAR in 2024 as he put up a 3.64 ERA (3.91 FIP) while running the lowest walk rate (6.5 percent) of his entire career. The A’s hit four home runs off of him a year ago, but they were all of the solo variety and accounted for all of their runs in the 13 innings Castillo spun against them. Shea Langeliers and Seth Brown have had the most success when facing Castillo of all current Athletics hitters, collecting five hits apiece in 31 combined at-bats.
On top of spending significant money on Severino, the A’s continued restructuring their rotation with an aggressive trade for Springs. The 32-year old southpaw underwent Tommy John surgery in 2023 and has just 33 major-league innings under his belt since his return on July 30 this past year. That includes five innings of scoreless ball in an August 27 start against the Mariners, in which he struck out Seattle hitters nine times, including Julio Rodríguez twice, and allowed just one hit. Given Springs’ handedness, this will likely mark the season debuts of Mitch Garver, Donovan Solano, and possibly Dylan Moore, barring any mid-game substitutions on Opening Day.
Game 3: RHP Bryce Miller vs. RHP Osvaldo Bido
Miller kicks off his second full-season in the majors against the team he made his MLB debut against. He only saw them once last year and gave up two runs on five hits while striking out nine and walking a pair, and has given up just six runs over 24 career innings against them. The A’s are a bit righty-heavy in their lineup, though two of their top-three hitters, Lawrence Butler and JJ Bleday, swing from the left side. Miller has struggled mightily when facing left-handed batters in his career, but he’s better equipped than ever to counteract them with a splitter that finished tops among all MLB starters in run value (+10) last year and a cutter that he spent this offseason refining. Plus, he’ll be where he’s most comfortable and dominant; the Texas A&M product limited opposing hitters to a laughable .179/.235/.282 slash line while running a 1.96 ERA (2.45 FIP) with a 30.3 percent strikeout rate at T-Mobile Park in 2024.
The Mariners got their first look at Bido in early September this past season and jumped on him quick, with Raleigh going yard for a two-run shot in the first inning. In all, Bido gave up four runs on six hits while striking out four in 5.1 innings in an eventual 5-4 A’s win. He finished the year having appeared in 16 games, starting nine of them, to the tune of a 3.41 ERA (3.36 FIP) and averaging just a smidge under a strikeout per inning (8.95 K/9). What stood out the most about Bido’s season was his elite ability to limit quality contact, placing in the 100th percentile in hard-hit rate (27 percent), 99th percentile in average exit velocity (85.6 miles per hour), and 93rd percentile in barrel rate (4.3 percent). As a result, the expected stats loved him, putting him in the 98th percentile in expected batting average (.181) and 94th percentile in expected ERA (2.72). That plus the general difficulty that comes with hitting at T-Mobile Park, particularly in late March, might lead to a long night for Seattle’s lineup.
Game 4: RHP Bryan Woo vs. LHP JP Sears
With George Kirby recovering from shoulder inflammation, Woo gets a shot to pitch in the first series of the year. While the assumption heading into every Woo start is that he’ll almost exclusively throw fastballs, his last two matchups against the A’s in 2024, just 22 days apart from one another, saw him mix in his secondaries, primarily his sweeper, a bit more than usual. That sweeper appeared quite a bit this spring as well, and was even his most-used offering in one of his Cactus League starts, so it shouldn’t come as a surprise if Woo goes to it with regularity in Sunday’s series finale. That approach worked well for him in those two aforementioned outings, in which he surrendered just a pair of runs on 11 hits and one walk while striking out 14 in 10 combined innings, with the sweeper generating seven whiffs on 13 swings.
Sears, a former Mariners prospect, will make his 10th career appearance against the team that drafted him in 2017. He’s handled them quite well so far, posting a 2.66 ERA (4.03 FIP) with a .191 opponent batting average in 50.2 innings pitched against Seattle. Generally speaking, though, Sears has been an average arm at best in his three-year career, amassing just 2.3 fWAR in 423 career innings with an ERA of 4.36 and a 4.81 FIP. So despite his successful track record against them, he provides by far the best matchup in this series for the Mariners on paper.
