SEATTLE -- The Mariners’ offseason all but concluded with their big trade for Brendan Donovan last week, which solidified a roster that should be favorites to repeat as American League West champions.
The 26-man roster undergoes a season-long fluctuation -- due to injuries, performance, etc. -- as evidenced by the 53 players that the club used last year, but Seattle has its core in place.
With that in mind, here’s a tentative look at how the group could look by Opening Day:
Catcher (2): Cal Raleigh, Andrew Knizner
Mitch Garver is gone (free agency), as is Harry Ford (traded to Nationals), which vacated Seattle’s backup-catching depth. That said, the area isn’t much of a need for a team that has the best backstop in baseball and plays every day. Knizner (one-year, $1 million free-agent contract) will be the leading No. 2 candidate over Jhonny Pereda (acquired in trade with Twins), who has one Minor League option remaining.
First base (1): Josh Naylor
Seattle’s front office was just as eager that it will get a full season of production from its prized Trade Deadline acquisition from 2025 as it was to being able to bring him back at the offseason’s outset, on a five-year, $92.5 million free-agent contract.
Second base (1): Cole Young
This spot is written in pencil, but sources familiar with the club’s thinking have indicated that Young is the favorite to retain the role he held for much of last year before scuffling down the stretch. And he’d have to really struggle in Spring Training for that to change. That said, Young might be the second-most discussed player in camp, given that he’s on a similar career trajectory and plays a position that could also be suited for Seattle's most intriguing player in camp -- No. 1 prospect Colt Emerson, who will be given the chance to play his way onto the team.
Third base (1): Brendan Donovan
Emerson is also in the mix here, and he probably would’ve had the cleaner path to an Opening Day roster spot had it not been for Seattle’s acquisition of Donovan, who will play all over but right now is penciled in for his most reps at the hot corner. Donovan is also expected to be the club’s everyday leadoff man.
Shortstop (1): J.P. Crawford
This will be a year of intrigue for the longtime clubhouse leader, who’s entering the final season of a five-year, $51 million contract. The 31-year-old bounced back from a brutal 2024 in '25, with a .352 on-base percentage while playing in 157 games. His longer-term future will be a leading topic of conversation this season, but for now, he’s a stabilizer at this premium position.
Left field (1): Randy Arozarena
Despite some defensive lapses and a glut of other corner outfielders expected to make the team, the Mariners firmly view Arozarena as their everyday left fielder and not a DH hybrid. The soon-to-be free agent is coming off a banner year, with a career-best 27 homers, 31 stolen bases and his second All-Star selection.
Center field (1): Julio Rodríguez
Durability was never a question last season, as he led MLB with 652 at-bats and played in all but two games. But whether he can finally put together his elite production over a full six months rather than more exclusively in the second half will be the prevailing narrative on one of the sport’s most talented players. Defensively, he’s still seeking his first Gold Glove Award.
Right field (2): Luke Raley, Victor Robles
This spot will tentatively feature a platoon, and among the roster’s biggest bounceback candidates, given that they were each sidelined with significant injuries in 2025. But how much of a timeshare each will have could be based on matchups and Cactus League performance.
Designated hitter (2): Dominic Canzone, Rob Refsnyder
Another platoon, and another that could be in flux as spring progresses. Canzone warranted an enhanced role after a breakout in 2025, when he hit .300 with an .840 OPS in 82 games. But his glove isn’t nearly as strong as the Raley/Robles tandem. Same for Refsnyder, who mashes left-handed pitching (.959 OPS last year) and was signed to a one-year, $6.25 million contract in December to do just that.
Utility/bench (1): INF Leo Rivas
Again, Emerson will be in the Majors this season, but with only 13 roster spots among position players, and that any time on the bench would impede his player development, he might -- for now -- be on the outside. Rivas won’t be, given that his switch-hit and positional versatility makes him Seattle’s ideal bench bat.
Starting pitchers (5): RHP Logan Gilbert, RHP Bryan Woo, RHP George Kirby, RHP Luis Castillo, RHP Bryce Miller
Keeping this group as healthy as possible could be what determines whether the Mariners run away with the division. Gilbert, Kirby and Miller were each on the IL for significant stretches in 2025, and Woo missed a full month leading into the playoffs. The depth behind them, at least on paper, isn’t as strong entering camp. That said, at its ceiling, the rotation could be among the sport’s best.
Relief pitchers (8): RHP Andrés Muñoz, RHP Matt Brash, LHP Gabe Speier, RHP Eduard Bazardo, LHP Jose A. Ferrer, RHP Carlos Vargas, RHP Ryan Loutous, LHP Robinson Ortiz
The 40-man roster features a pile of relief pitchers who will compete for two spots. Loutous and Ortiz being the leading candidates is mostly a guess at this point, as there is an army of unheralded arms the club has added from outside the organization this offseason.