Mariners' spring training plans include unexpected Colt Emerson game-changer

Whatever chance there was of the Seattle Mariners returning Eugenio Suárez to the hot corner in 2026 officially went "poof" on Sunday. He signed with the Cincinnati Reds, which all but confirms third base as a job to be won in Peoria this spring.

Even before they lost "Geno" to the Reds, the Mariners weren't being subtle about their desire for third base to be filled by an in-house option. It was going to be Ben Williamson vs. Colt Emerson at first, but now it's set to be Emerson vs. Brendan Donovan after Seattle finally pulled off a trade for the 2025 All-Star on Monday.

Though Donovan mostly played second base for the St. Louis Cardinals, he has experience at third base and Adam Jude of The Seattle Times says the Mariners view him as viable at the hot corner:

Granted, Donovan at third base on Opening Day doesn't feel like an especially likely outcome. He's likely to begin spring training with a leg up on Cole Young for the second base job, with Emerson getting more of a clear runway to win the third base gig.

But then again, Donovan at third and Emerson at second may be one of those "stranger things have happened" sorts of deals.

The door is apparently open for Colt Emerson to break camp as the Mariners' second baseman

Though the Mariners have spent the winter conditioning the fanbase to expect Emerson — a natural shortstop who ranks as MLB Pipeline's No. 9 prospect — to play third this spring, second may be there for his taking as well.

Take it from Daniel Kramer of MLB.com, who noted on Friday that Emerson "is expected to be in the mix at second" in addition to third base this spring. This wouldn't seem to be a rug-pull for the 20-year-old prospect, who has reportedly been working out at the keystone during the offseason.

Playing Emerson at second would mean moving him to the right side of the infield, which may not be ideal if the long-term plan is to have him take over for J.P. Crawford at shortstop in 2027. And since Young has only ever played on the middle of the infield as a professional, it'll be hard for the Mariners to clear reps at second for Emerson by playing Young elsewhere this spring.

Even so, the notion that third base isn't Emerson's only avenue to a starting job is noteworthy — if for no other reason than it doesn't take a strong imagination to envision how things could work out.

Despite his relative inexperience at third, Donovan actually has more career Defensive Runs Saved there (6) than he does at any other position. If he lives up to that, having him play third could reveal itself to be not just viable, but potentially a major advantage.

If that happens, Young might find himself under sudden pressure to hold off Emerson at second base.

Though Young was a top-100 prospect just last year, his stock is down after he managed just a .607 OPS in 77 games with the big club last year. Emerson's stock is way up after he raked at three different levels in the minors last year. And whereas Young was exposed as a subpar defender last year, the book on Emerson is that he's gifted in the field.

That alone could influence the Mariners' ultimate decision. Infield defense is a clear target for improvement in 2026, and an alignment that has Donovan at third and Emerson at second may well end up being the club's best hope of nailing it.

Granted, all of the above feels like overthinking a small part of a bigger story. But if the Mariners are serious about giving Emerson every opportunity to earn a job, it only makes sense that he would have more than one job to earn.