As the Mariners roll into Spring Training, all eyes are on the infield - and for good reason. Seattle made some of its biggest offseason splashes here, re-signing Josh Naylor and swinging a trade for Brendan Donovan. Those moves helped offset the departures of Jorge Polanco and Eugenio Suárez, but they also signaled a broader reshaping of what might be the most complete roster in the American League.
Let’s start with what we know. Naylor is locked in at first base.
J.P. Crawford remains the anchor at shortstop.
And Donovan, acquired in a three-team deal, is expected to be an everyday presence - though exactly where he plays could depend on how the rest of the infield shakes out. He’s a steady glove at second base and has experience in the outfield corners, but early work with infield coach Perry Hill suggests the Mariners are eyeing him at third base, at least to open camp.
That’s the cleanest short-term fix. With Suárez gone and Ben Williamson - another third base option - shipped to Tampa Bay in the Donovan deal, the hot corner is wide open.
Of the five players who started at third in 2025, only Miles Mastrobuoni is still in the organization. Donovan didn’t see any time there last season, but he’s logged nearly 270 innings at third from 2022 to 2024.
That’s not a huge sample, but defensive metrics like Defensive Runs Saved and Outs Above Average have liked what they’ve seen so far.
Still, Donovan’s ultimate role could hinge on how Seattle’s younger infielders perform. Cole Young is the early favorite at second base, despite a tough ending to his rookie campaign.
The former first-rounder showed plenty of promise in the minors, slashing .279/.388/.432, and is still just 22. He’s no longer technically a prospect, but the upside is very much still there.
Then there’s Colt Emerson - and this is where things get interesting. The 20-year-old shortstop is one of the most highly regarded prospects in the game.
After being drafted in the first round in 2023, Emerson tore through three levels of the minors last season, hitting .285 with 16 homers, 14 steals, and a plate approach that’s well beyond his years. He walked nearly 12% of the time and struck out in under 18% of his plate appearances - rare discipline for a player his age.
He even earned a late-season look at Triple-A, playing six games in Tacoma to close out the year. Across the board - from Baseball America to ESPN - Emerson is viewed as a top-10 overall prospect.
The expectation is that he’ll begin 2026 in Triple-A, but the Mariners aren’t ruling out a surprise. “It’s not out of the question that he earns a spot on the team,” said president of baseball operations Jerry Dipoto, who praised Emerson’s maturity and all-around game.
Assuming Emerson starts in Tacoma, the projected Opening Day infield looks like this: Naylor at first, Young at second, Crawford at short, and Donovan at third. Emerson will likely get steady reps at third base in Triple-A - he’s logged just over 110 innings there as a pro - with an eye on a midseason call-up. Long-term, he’s probably Crawford’s successor at shortstop once the veteran hits free agency next winter, but don’t expect a position change this year unless Emerson absolutely forces the issue.
And if he does? The Mariners have flexibility.
Donovan could shift back to second, where he’s more than comfortable, and Young - who still has minor league options - could head to Tacoma. That’s a scenario the team is prepared for, even if Donovan doesn’t log much time at second during camp.
One name flying a bit under the radar is Ryan Bliss. He opened last season as the Mariners’ second baseman and was off to a solid start before injuries derailed his year.
Bliss ruptured his left biceps just two weeks into the season, underwent surgery, and later suffered a meniscus tear in his right knee during a September comeback attempt. But before all that, he was raking in Triple-A - .269/.377/.456 with 12 homers and 50 stolen bases.
He’s back to full health this spring and looking to reassert himself in the infield mix.
It’s a deep group, and it’s only going to get more crowded once Emerson is ready. Bliss still has a couple of options remaining, which gives Seattle some roster flexibility.
Same goes for Leo Rivas, who quietly reached base at a .387 clip in 111 plate appearances last season and earned a spot on the postseason roster. Both players are in the mix, but the roster math gets tricky fast.
Mastrobuoni and Luke Raley, who were essentially platoon bench bats down the stretch, are both out of options. That puts Seattle in a tight spot.
They’ll need to carry backup catcher Andrew Knizner and right-handed bat Rob Refsnyder. Keeping both Mastrobuoni and Raley likely means optioning Bliss and Rivas - and that’s before even considering Emerson’s arrival.
Dipoto acknowledged the squeeze, noting that the front office may have to make “some uncomfortable short-term decisions” before Opening Day. That’s the cost of depth - and the Mariners have it in spades.
This infield group is talented, versatile, and brimming with upside. Now it’s just a matter of how the pieces fit - and who forces their way into the picture.