The Mariners have already spent this season promoting prospects at a pace that would make most farm systems blush. Kade Anderson, Lazaro Montes and Michael Arroyo arrived in the big leagues within two weeks of one another, and Colt Emerson was in the mix before them. That’s four top-100 prospects debuting in one season, which is not exactly routine.
So the next question practically asks itself: who’s next, and how soon?
Ryan Sloan looks like the most likely answer. The 20-year-old right-hander is ranked No. 2 in the Mariners’ system by MLB Pipeline and is currently at Double-A, with an MLB ETA of early 2027.
Even so, it wouldn’t be shocking if Seattle got a look at him before 2026 ends. Mariners prospects moving from Double-A to the majors has become a familiar path, and Sloan has the kind of build and arsenal that make him easy to dream on.
He’s 6-foot-5, 220 pounds, can run his fastball up to 100 mph, pairs it with a nasty sweeper and, most importantly, throws strikes.
His season has really taken off after a rough opening stretch. Sloan started with a 5.09 ERA and an .802 OPS allowed over his first 10 starts.
Over his last 11, he’s posted a 2.70 ERA and a .585 OPS, with 73 strikeouts and just three walks. Yes, three walks.
That’s the part that jumps off the page.
Boston Smith is another name moving into the conversation fast. The catcher/left fielder/designated hitter is ranked No. 13 in the system and is also at Double-A, though he’s only been in the organization for a few weeks after coming over from the Chicago White Sox in the Luis Castillo trade.
He wasn’t viewed as the headliner at the time. He might be now.
Smith, a sixth-round pick by the Washington Nationals in the 2025 draft, has put together one of the loudest bats in the minors this year. He’s hit .274/.430/.578 with 31 home runs, and his 162 wRC+ is tied for second among all MiLB hitters with at least 450 plate appearances.
The defensive fit is still unsettled, but Seattle has every reason to push the bat. If Smith starts next season at Triple-A, he’ll be knocking on the door.
Jonny Farmelo is still very much in the mix too. The center fielder reached Double-A at the same time as Felnin Celesten, who was generally seen as the better prospect.
Celesten’s season went sideways from there, as he put up a .507 OPS in 31 games with Arkansas before being shut down with a groin injury. Farmelo, meanwhile, has stayed on the field enough to play 124 games after injuries limited him to 75 games in both 2024 and 2025.
He’s been productive when healthy, too: an .810 OPS, 15 home runs and 40 stolen bases. The one drag is a slump at Double-A, where he’s down to a .697 OPS. Even so, he remains a prospect to track closely and could be in line for the Montes/Arroyo treatment around this time next year, maybe even sooner if he gets hot again.
And while Ace Reese isn’t quite in the same call-up lane yet, he’s already forcing the Mariners to think about how fast they’re willing to move a player. The third baseman is ranked No. 8 in the system and was drafted just a few weeks ago at No. 24 overall, but he’s done nothing to slow the buzz. In 21 games with Inland Empire, Reese has hit .440/.530/.667 with eight doubles and three home runs, while drawing 19 walks and striking out only 12 times.
That’s the kind of start that gets attention, especially since he was also a standout hitter at Mississippi State. It’s early, and nobody should expect him to keep racing forward like this forever, but he’s already done enough to make people wonder how long Seattle will wait.
In Other News...
Mariners Still Waiting As Brendan Donovan Hits A Recovery Roadblock
Brendan Donovans recovery from the concussion he suffered Aug. 22 in the batting cages has been slower than the Mariners would like, with symptoms such as dizziness and nausea continuing to interrupt his progress through the concussion protocol. Donovan has been monitoring the process with a wearable device, and he confirmed he was not wearing a helmet when the injury occurred, a detail that underscores how routine work can still turn into a long absence.
For Seattle, the latest update from general manager Justin Hollander leaves Donovan still on the shelf and not yet ready to return to play. The Mariners are left waiting on a player whose timeline has been pushed back by a roadblock that is hard to predict and even harder to speed up, especially when concussion symptoms keep lingering instead of clearing. [Read more 🡒]
Mariners Suddenly Have A 2027 Problem They Cant Ignore
Matt Brashs latest shutdown is another reminder that the Mariners have spent much of this season managing not just a roster, but a series of health questions that keep changing shape. Right lat inflammation has taken him out of the mix again, while Brendan Donovan is still only inching forward from the concussion he suffered on Aug. 21, leaving Seattle to piece together both bullpen help and lineup depth around two players it had reason to count on.
The immediate concern is obvious, but the longer view may be even trickier. Both players have already missed significant time this year, and the uncertainty around when they can be counted on again forces the Mariners to think beyond the present standings race and into 2027 planning. A team can survive one injury cluster, maybe even two, but not when the question lingers over whether these pieces will be stable enough to build around at all. [Read more 🡒]
Michael Arroyo Just Made Seattles Long Term Question More Urgent
Michael Arroyos call-up gave the Mariners another look at one of the organizations top young bats, and it also sharpened a conversation that had already been lingering in the background. The third-best prospect in Seattles system arrived with a reputation as a strong hitter, which is exactly why the club wanted to see him against big-league pitching, but his defensive profile has always complicated the fit. He has been used mostly in left field, and thats where the Mariners have to decide whether his bat can outweigh the concerns that come with his glove.
For Seattle, the timing matters as much as the talent. Arroyos debut comes with the front office still sorting out how he fits into the long-term picture, and left field is one of the clearest places to watch. Randy Arozarena is getting closer to free agency, so the Mariners are suddenly weighing not just what Arroyo can do right now, but whether he could be part of the answer if the roster starts changing around him. [Read more 🡒]