Much of the focus in Mariners camp will be on the infield. Seattle’s biggest offseason moves — re-signing Josh Naylor and trading for Brendan Donovan — addressed two spots. They lost a couple infielders, Jorge Polanco and Eugenio Suárez, to free agency. It’s the biggest area of turnover on what might be the American League’s best roster.
Naylor and J.P. Crawford are locked into first base and shortstop, respectively. Donovan will be an everyday player. He’s a solid defender at second base and can handle the corner outfield as well, though his below-average speed means he fits better on the infield. Ryan Divish of The Seattle Times writes that Donovan’s early work with infield coach Perry Hill has come at third base.
That’s the simplest solution in the short term. Suárez and Ben Williamson, who was traded to Tampa Bay in the three-team Donovan deal, took the majority of the playing time last season. Of the five players who started games at third base in 2025, only Miles Mastrobuoni remains in the organization. Donovan didn’t get any work at the hot corner last year but logged 269 2/3 innings there between 2022-24. Although defensive grades aren’t especially meaningful in that small a sample, he has above-average marks from Defensive Runs Saved and Outs Above Average.
Donovan’s primary role will largely be determined by the progress of younger players around him. Cole Young had a brutal finish to his rookie season, but he remains the favorite to start at second base. Young is a former first-round pick who hit .279/.388/.432 in the minors and is entering his age-22 season. He remains a very promising young player even though he’s not technically a prospect anymore.
20-year-old shortstop Colt Emerson is even more highly regarded. The 2023 first-round pick combined for a .285/.383/.458 batting line with 16 homers and 14 steals over 600 plate appearances across three minor league levels. Emerson walked at a near-12% clip while striking out less than 18% of the time. He spent the majority of the season in High-A but ripped through Double-A to earn a late-season cameo at Triple-A Tacoma. He played six games there in the final week of the regular season.
Emerson is a consensus top 10 overall prospect at Baseball America, The Athletic, ESPN and MLB Pipeline. The likeliest outcome is that he opens the season at Tacoma with an eye towards a midseason promotion. It’d be a surprise if Emerson breaks camp, but the Mariners aren’t completely closing the door on that as Spring Training opens. “It’s not out of the question that he earns a spot on the team,” president of baseball operations Jerry Dipoto told reporters on Thursday (link via Daniel Kramer of MLB.com). Dipoto praised Emerson’s well-rounded skillset and maturity.
The probable Opening Day infield lines up as Naylor, Young, Crawford and Donovan from right to left. Emerson could get consistent reps against Triple-A pitching while building reps at third base, where he has 111 1/3 innings of professional experience. He’s the heir apparent at shortstop when Crawford hits free agency next winter but presumably wouldn’t push the veteran off the position this year. If Emerson has a monster Spring Training that forces the club’s hand, Donovan could kick back to second base and potentially move Young to Triple-A. That shouldn’t be an issue even if Donovan doesn’t play any second base during Spring Training given his ample work at the position.
Last year’s season-opening second baseman, Ryan Bliss, hasn’t gotten as much public attention. Bliss is older and not nearly as highly regarded as Young and Emerson, so that’s natural, but he’s a former second-round pick who hit .269/.377/.456 with 12 homers and 50 stolen bases in Triple-A in 2024. He unfortunately didn’t get much of an opportunity to solidify himself at the MLB level.
Bliss ruptured his left biceps on a swing two weeks into the regular season. He underwent surgery that came with a 4-5 month rehab timeline. Bliss returned to minor league game action in September and had an impressive week in Triple-A. He may well have reclaimed the second base job from Young to close the regular season had he not sustained a meniscus tear in his right knee that required season-ending surgery. Kramer writes that Bliss is back to full health this spring.
It’s a deep infield that’ll only become more crowded whenever Emerson earns the call. Bliss has a couple minor league options remaining. Leo Rivas also has an option but reached base at a .387 clip in 111 plate appearances last season and made the team’s playoff rosters. They flip-flopped Mastrobuoni and Luke Raley as the last hitter off the bench in October.
They’re both out of options, and it’s difficult to see Seattle carrying both players into the season if all their hitters get through camp healthy. They’ll need bench spots for backup catcher Andrew Knizner and righty platoon bat Rob Refsnyder. Keeping Mastrobuoni and Raley would require them to option both Bliss and Rivas before even considering an Emerson promotion. Dipoto acknowledged the likelihood that someone gets squeezed out at the end of Spring Training, conceding the front office may “have to make some uncomfortable short-term decisions.”
it will be interesting to see how things get sorted out here. Losing both Suarez, and Polanco is going to hurt a bit.
Masturbouni doesn’t have the bat to be an everyday player even if he was well-protected and batted 9th. Donovan might start there but one of the youngins will have to replace him eventually
Mastrobuoni probably doesn’t make the roster.
Even Rivas might not make it, if they determine that Emerson and Young are both ready.
Donovans value is more about his versatility rather than him being a good defender at one particular position. Injuries will happen and he will fill in and then when Emerson is ready they can work that out too.
You are getting a good player in Donovan. He does have a gold glove as well. He gives 110% on every at bat and every play in the field and very tough and gritty. He will be missed in STL.
I’m very curious to see how he does, as he was matched with the Dodgers for a lot of the off-season, and didn’t see the fit, given their internal options..
Sounds like a strong acquisition for them.
Really sad Bliss got hurt last year. Think the guy has a shot to be a good player but I just dont seem him getting playing time this year barring catastrophe.
They’ll most likely option Bliss and Emerson will start in Tacoma. Bliss needs some time to play the game of baseball, having only played a few games last year. Rivas is solidly on. And if Emerson hits .500 in spring with 100 home runs, he’s the starter at 3B with Donovan moving to 2B and Young going down. He has to play every day (he’s only 20), so it’s likelier that Young stays at 2B and Emerson goes to Tacoma. I hope they can squeak Mastrobuoni through a DFA and retain him in Tacoma when all the other teams are DFAing guys.
They wouldn’t need to DFA Mastrobuoni if Young starts the season in Tacoma.
All reports are that they love Cole Young. Technically, of course, you’re right.
Young didn’t get the chance to go down to AAA and work on things once he got overmatched and off track last season.. Seattle kept him on board and sat him down the stretch and in the postseason. I know Seattle’s high on him, Dipoto himself suggested he expects Young to break out.
But that doesn’t mean he should be (or is) a lock to make the team. If it were my call, he would start the season in AAA. It’s not just his offense, he was one of the worst defenders at second last season. There’s a lot to prove still.
That said, Seattle has pushed their luck with prospects time and time again. They’ve hit on 2 and whiffed on many (in the Dipoto era). I don’t think they’ve learned, so it wouldn’t surprise me if Young breaks camp with the team. I could see them getting excited about a small string of decent PAs in spring and rolling the dice.
I hope he is successful, of course. I just worry about his readiness and I think Mastrobuoni did a respectable job last season. He’s clearly the odd man out given the number of LHHs in the infield, but that might be a better timed move in June or July.
Comparing Raley to Mastrobuoni is apples to oranges. They are both older (Raley is 31, Mastrobuoni a year younger). While Raley had a terrible, injury plagued 2025, he was a very solid lefty bat in 2023 and 2024 (average: 430PAs, 3 bWAR, 126 OPS+). While he’s had much less playing time, Mastrobuoni is a career 64 OPS+ hitter. Mastrobuoni can cover 3B adequately, which Raley can’t, but Raley is more than adequate in the OF and OK at 1B. The only reason to keep Mastrobuoni is that the Ms now have a similar player to Raley in Canzone, and if Raley has a good spring one might get something for him in a trade..
Anthony wasn’t comparing the two. He simply pointed out that those two are the most expendable. They don’t need two lefty platoon outfielders/DH and they have too many lefty-swinging infielders.Raley isn’t needed at first, regardless.
Neither seem likely to stick around when/if both Young and Emerson are on board, it’s more of a question of who goes first.
As always, Stevil, you’re right. The only fly in the ointment would be if Canzone has as horrible a ST as he did in the playoffs. He still has an option left, so they might send him down to keep Raley, even after Emerson comes up. The operative word is might.
The postseason was a very small sample against very good pitching. I don’t think that did anything to jeopardize his standing with the team.
Keep in mind spring results aren’t going dictate much. They’ll be looking at process. That goes for Young as well.
Mariners infield would appear to be ignorance
“It’s the biggest area of turnover on what might be the American League’s best roster.”
That is not the American League’s best roster whatsoever. I do not believe the projections. I would say Yankees.
A big question mark for the Yankees is how their injured pitchers recover and impact the season. I think the offensive profiles are very similar, and Seattle’s pitching appears to be *crossing fingers* healthier to start the year.
Troll
Saying the Yankees have the best AL roster over the blue jays or even Red Sox is hilarious they have Anthony Volpe starting at shortstop
You would say this Astro 71.
A healthy season out of Victor Robles will make a big difference. Robles is a difference maker. Mariners lineup looks solid with a full season of Naylor and the addition of Donavan, best lineup they have put together heading into spring in years. Bench is strong too with Refsnyder and Raley.
Their depth at C is lacking, could see them adding a catcher.
Biggest question mark in Seattle is the durability of Logan Gilbert, George Kirby and Bryce Miller.
Id think they would be moving Sloan and/or Anderson along but unlikely that either will be an option this season. That leaves them with Criswell, Hancock and Dunning as depth for the rotation.
If they have injuries to the rotation and the bullpen, they will certainly be cashing some prospects for a starter and a bullpen arm or two at the deadline.
3 pitchers as depth. I wouldn’t rush Sloan or Anderson as well. Criswell, Hancock, and Dunning are not very great depth options.
Troll
Well the starting pitching depth could be a real problem fast.
Catchers? I’m counting four.
All these guys with injuries some teams worse then others. Conditioning is a big. Part of staying injury free. Some player are able to do well in escape injuries.
Even without Geno and Polanco that is going to be a scary good Mariners team.
In the off chance Emerson starts the year in the majors I think they’d be better off sending canzone down to AAA and keeping young at 2b. Donovan would platoon in right with robles and get some starts at 3B and 2B
What if Emerson, Young, and Canzone all stayed in the majors.
Donovan might play one day per week at DH, 2B, and 3B for Canzone, Young, and Emerson
He could play 2 days per week in RF, for Raley
Additionally, he’d play 1 day every other week in LF and at least one day extra per month (in RF) while Robles covers center.. That might be as much as 23 out of every 25 games.
Meanwhile, you don’t want Young and Emerson to play more than 5 times a week while they’re still adjusting. And I’d like both Randy and Julio to play slightly fewer games this year than last. Only Raley gets shortshrift. If he’s playing well, that time might come from Canzone, Young, Emerson or even Naylor, who also shouldn’t play 155 games. (When Naylor’s out, Ref’s probably at 1b, and Donovan at DH.)
Wilson just has to give up the obsession with using a poor-hitting RHH over a good-hitting LHH against Lefties.
Only so many roster spots though. One of Rivas, canzone, Emerson or young has to be sent down as they’re the only ones with options. Could also trade raley or jp but I’d rather not
Sure. I just don’t believe Rivas has a lock on a roster spot.
He isn’t needed for his defense, if Colt and Cole are both around.
I’m skeptical of his bat holding up with continued exposure.