SEATTLE -- It’s a busy time of year down on the Mariners’ farm.
Seattle just promoted its top two hitting prospects to Triple-A, where they’re off to a hot start. It sent its top two pitching prospects to Philadelphia for the Futures Game, where they shoved against some of the Minors’ top hitters. And it got its latest influx of prospects at the Draft, bolstering a system that began the year as loaded as anyone’s.
A new Draft also means that it’s been a year of professional baseball for last year’s class. Fifteen of the Mariners’ 21 2025 Draft picks are currently playing for the organization; two didn’t sign, three have been traded and one (third-round pick Griffin Hugus) underwent Tommy John surgery.
COMPLETE MARINERS PROSPECT COVERAGE
With one 6-foot-2, left-handed exception in Arkansas -- more on that below -- they’re still a ways off from impacting the big league club. But now that they’re no longer the freshmen of the organization, let’s catch up with a few members of the Class of ‘25, a year (plus a week) after they heard their names called in Atlanta.
Kade Anderson, LHP
It’s important to remember that for all the fanfare Anderson came with last July, the Mariners kept him off the mound all summer and fall to rest -- then dropped him straight into big league Spring Training, then had him begin his professional career in Double-A. All of those challenges could have slowed down the hype. But instead, that hype’s only grown with Anderson posting a 1.36 ERA and a 0.69 WHIP in a Texas League that usually skews hitter-friendly, with 108 strikeouts in 72 2/3 innings. Last Sunday, he needed just 10 pitches to roll through the first inning of the Futures Game.
Seattle’s rotation is already jammed with six starters, but Anderson is doing his best to force the organization’s hand for a potential callup before season’s end.
- Round: Competitive Balance (No. 35)
- Prospect ranking: No. 7
- Current team: High-A Everett
After slashing .280/.460/.400 in 100 plate appearances at Single-A last year, Stevenson -- now the system’s highest-ranked catcher -- has been a bit more of a power hitter in High-A. His batting average has dropped 43 points and his strikeout rate jumped from 19% to 27.9%, but his OPS has stayed relatively steady thanks to 10 home runs, 17 doubles and a system-leading 66 walks. And he’s currently on a tear, hitting .351 in July with four homers.
Mason Peters, LHP
- Round: 4 (No. 122)
- Prospect ranking: No. 14
- Current team: Single-A Inland Empire
Anderson (and Ryan Sloan) are always going to overshadow just about every pitcher in the system, but what Peters has done at Inland Empire -- while still far away from Seattle -- is arguably as impressive. He hasn’t pitched since mid-June due to forearm tightness, but much of that is due to caution; his MRIs came back clean. Of Mariners Minor Leaguers with at least eight starts, Peters’ 1.41 ERA, 0.83 WHIP and 12.69 K/9 all rank second, only behind -- take a wild guess -- Anderson.
Lucas Kelly, RHP
- Round: 6 (182)
- Prospect ranking: No. 27
- Current team: Everett
If there was a theme for the Mariners’ 2025 Draft, it was pitchers with different arm angles, and Kelly led the charge in that regard with a funky delivery that plays up his fastball and slider. After a slower start, Kelly found a groove in a scoreless June -- complete with 15 strikeouts in nine innings -- that earned him Mariners Minor League Reliever of the Month honors.
Jackson Steensma, RHP
- Round: 9th (No. 272)
- Prospect ranking: No. 29
- Current team: Inland Empire
If there’s a positive outlook for Peters, it could be Steensma’s path this year. The right-hander allowed three earned runs in his first 19 innings before experiencing forearm soreness. With MRIs all clean, Steensma -- who underwent Tommy John surgery in college -- still took two months between outings. He made his return to the mound last Friday and looked good, allowing just one hit in two scoreless innings.
Aiden Taurek, OF
- Round: 13 (No. 392)
- Prospect ranking: No. 28
- Current team: Inland Empire
Taurek hit .336 in Single-A last summer and has followed that up with another solid season. He leads the Mariners’ farm system with 29 doubles, ranks second in triples with five and sits in the top 10 in hits (81), RBIs (51) and walks (44).
Estevan Moreno, INF
- Round: 20th (No. 602)
- Prospect ranking: N/A
- Current team: Inland Empire
The club's final pick last year, Seattle was mainly interested in Moreno’s defense and his arm, even floating the possibility of converting him to pitcher. Somebody forgot to tell Moreno that, though; in 56 games with the 66ers he’s posted a .500 slugging percentage thanks to 10 homers (tied for the team lead), 15 doubles and three triples.