Down on the Farm: Midseason Check-In on Mariners’ Top 5 Prospects

Despite the mediocre start to the season for the big league club, it’s an exciting time to be a Seattle Mariners fan. The major league club is squarely in contention for the AL West and even still could be considered the favorite in the division, in large part due to young players stepping up and playing big roles.

In the midst of a hot streak, 22-year-old Cole Young leads the team in bWAR (2.8) and is fresh off a multi-homer game on Monday against the Angels. Despite a recent slump, top Mariners prospect Colt Emerson is managing an above-average 104 OPS+ with seven homers in 36 games thus far. And away from those two players, more help may soon be on the way to the majors to help the cause in the second half.

How are the other exciting Mariners prospects doing that are yet to make their MLB debuts? Let’s dive into the top five prospects (per MLB Pipeline) in Seattle’s organization for a midseason check-in:

Kade Anderson, LHP (#1 SEA, #5 MLB)

Not only is Anderson the Mariners’ top prospect right now, he’s the top left-handed pitching prospect in the entire sport, and he’s lived up to the billing. That alone should get Seattle fans excited for his inevitable arrival soon. Now, go look at his numbers this season in Double-A Arkansas. After going third overall in the 2025 draft out of LSU, Anderson looks to be taking the fast track to the big leagues.

In 66 2/3 innings through Monday, he has dominated to the tune of a 1.22 ERA. That is the best mark among any pitcher in the Texas League with at least 35 innings pitched this season. His 99 strikeouts is 14 more than the next best pitcher. It’s starting to become impossible to justify leaving him off the MLB roster. Perhaps after the trade deadline, a spot will open up, potentially helping out a bullpen that has struggled as of late.

Ryan Sloan, RHP (#3 SEA, #9 MLB)

Sloan lives somewhat in the shadow of Anderson, but he’s still a top 10 prospect in all of baseball in his own right. He hasn’t had the same meteoric rise as Anderson, nor is he dominating at the same level in Double-A. Still, he’s just 20 years old. He owns a 4.11 ERA in 57 innings for the Travelers. He has a solid three-pitch mix, which includes a devastating changeup.

With a massive 6-5 frame and a repeatable delivery, it won’t be long until Sloan finds his groove and also knocks on the door of the Mariners clubhouse. In case you are worried about that higher-than-average ERA, he is the second-youngest pitcher in the Texas League and holding his own, positioning him to possibly be a late season callup to fortify the bullpen as well.

Lazaro Montes, OF (#4 SEA, #28 MLB)

Signed for $2.5 million in 2022 out of Cuba, Montes was coveted for his raw power. At a hulking 6-5 and 210 pounds, he can certainly send baseballs a long way from the left side of the plate. He has been doing that in bunches thus far in his minor league career. After blasting 32 home runs between High-A and Double-A last season, he already has 23 this season for Double-A Arkansas. That’s second best in the entire Texas League, even as he is just one of a dozen or so hitters 21 or younger in the league.

Posting a .917 OPS and 142 wRC+ suggest Montes is handling Double-A pitching day-in and day-out just fine. He may earn a late season promotion to Triple-A if he keeps slugging like this with an ETA for the majors likely coming in early 2027.

Michael Arroyo 2B/OF (#5 SEA, #45 MLB)

Arroyo came from the same international signing class as Montes, but from Colombia. That class may turn out to be extremely fruitful for Seattle. However, that is basically the only thing in common he has with Montes. At 5-10, 160 pounds, his compact athleticism provides a good combination of speed and power. He separates himself with his athleticism and versatility, as he has split time between second base and left field this season for Double-A Arkansas.

Arroyo fills the box score nicely, currently batting .276 with eight homers, 11 doubles, and 11 stolen bases this season. That rounds into a .792 OPS and 119 wRC+ in 59 games thus far, and like Montes, 2027 may be the sweet spot for him to start making a push at the majors.

Jonny Farmelo, OF (#6 SEA, #65 MLB)

Speaking of athleticism, Farmelo has it in spades. He might be one of the best pure runners in the minor leagues, regardless of position or level. With an .834 OPS in High-A for the Everett Aquasox, he is getting on base plenty enough to show off that speed. That has resulted in 22 stolen bases, fifth-most in the Northwest League. The Virginia native is a bona fide centerfielder as well, offering defensive upside that would be welcomed down the road by the big league club.

What will set Farmelo apart is his ability to work walks at the plate, with his 15.9% walk rate this season. That ranks among the leaders in the league. Plus, he can pull a homer when the opportunity arises, with 10 dingers so far in 2026. There’s a veteran logjam in Seattle right now, but he’s yet another player who could start to make waves as a callup option next year.