When could top pitching prospects join Mariners? An expert’s prediction

The Seattle Mariners already have a crowded collection of starting pitching at the major league level, which has forced them to get creative in how they deploy a rotation that currently features six healthy arms.

Passan: Trade deadline comment by Mariners GM Dipoto ‘interesting’

On top of that, the M’s also have two of the top pitching prospects in all of baseball: 2025 first-round draft pick Kade Anderson and 2024 second-round pick Ryan Sloan.

How soon could Anderson and/or Sloan get called up to the majors? MLB Draft expert Joe Doyle of Over-Slot Baseball was asked that question during this week’s edition of Extra Innings on Seattle Sports.

Anderson’s timeline

Anderson, the No. 3 overall pick in last year’s MLB Draft, is having a sensational pro debut at Double-A Arkansas this season.

The 22-year-old left-hander has recorded a dazzling 1.36 ERA over his 14 starts, highlighted by a streak of 27 2/3 consecutive scoreless innings from May 22 through June 19. He leads the Texas League in virtually every major pitching category, including ERA, strikeouts (108), WHIP (0.69), opponents’ batting average (.160), strikeout rate (41.4%) and walk rate (3.8%).

Doyle believes Anderson is knocking on the door of an MLB promotion for the Mariners’ stretch run – with the only question being whether he joins the bullpen or the M’s somehow make room for him in the rotation.

“I think Kade Anderson is going to be a Mariner in 2026,” Doyle said. “I just don’t think there’s any way that you leave that arm talent on the sidelines in a World Series push – be it in the bullpen or be it in the rotation.

“I don’t really think it matters where he pitches, as long as he pitches 25 to 30 innings for the Seattle Mariners in late August and in September. … I think you see him probably by Aug. 20 at the latest.”

Sloan’s timeline

Some prognosticators believe the 20-year-old Sloan ultimately has an even higher ceiling than Anderson, even if he hasn’t been as dominant yet.

Sloan has 4.04 ERA in 14 starts with Arkansas this season, including a 2.07 ERA over his past four outings. The 6-foot-5 right-hander has piled up 77 strikeouts and 12 walks in 62 1/3 innings – highlighted by a perfect six-inning, 11-strikeout outing on May 30.

Doyle doesn’t think the Mariners will call up Sloan this season, due to the impending threat of a 2027 MLB lockout and how that could impact Sloan’s development. At the moment, Sloan probably needs more development time than Anderson, given that he’s 1 1/2 years younger and went straight from high school to the minor leagues.

“If there is a work stoppage in 2027 and there’s no baseball, anybody that’s on the 40-man roster is ineligible to pitch anywhere,” Doyle said. “And so with that in mind, I would be surprised if Seattle wanted to risk taking away from Ryan Sloan’s development in 2027.

“You’re building up all these innings, you’re taking good care of him. It would be a pretty big hit to the system if Ryan Sloan was only able to pitch 40 or 50 innings in 2027 if there was a lockout into June or July. But if he’s not on the 40-man, they can pitch him in Tacoma all season, where there’s going to be baseball.”

Listen to the full conversation with Over-Slot Baseball’s Joe Doyle at this link or in the audio player near the top of this story. Catch Extra Innings from 7-9 p.m. on Mariners off days throughout the season.

Seattle Mariners news and more

• Mariners Trade Deadline: What’s the market for right-handed bats?
• Mariners can cast a wider net than others at trade deadline
• Seattle Mariners Mock Draft Roundup: Four names to know

Related

Happ, Ramirez power Cubs to 19-2 rout of MarinersRandy Arozarena reaches milestone with leadoff HRMariners place Brendan Donovan on concussion ILFormer Mariner Jarred Kelenic DFA’d by RangersHow to find Sunday’s Seahawks, Mariners games on radioMariners’ Kade Anderson takes it all in before impressing in debut