Mariners fans should take whispers of a major improvement with a grain of salt

The Seattle Mariners were a joy to watch as they made their run to Game 7 of the ALCS last year, but there was always a caveat. Whenever a ball was hit into play, you held your breath and hoped calamity didn't ensue.

Sure, they ranked toward the bottom of the league in errors and, accordingly, toward the top in fielding percentage. But it's not 1999 anymore, folks. They've had more holistic defensive metrics for a long time now, and two of them rated Seattle's 2025 defense as one of the worst in baseball.

Per their -27 Outs Above Average, they were the fourth-worst defensive team of 2025. They fared better (i.e., 18th) per their +9 Defensive Runs Saved, but they would have been right at zero if it hadn't been for Julio Rodríguez's heroics out in center field.

But now for the part that would have Professor Farnsworth going, "Good news, everyone!" Mike Petriello of MLB.com recently highlighted defensive projections for 2026, and the Mariners are slated to be one of the five most improved teams in the league.

The Mariners are projected to be better defensively in 2026, but how?

As Petriello notes, Julio and Cal Raleigh are Seattle's "only true obvious pluses" in the field. But Jorge Polanco being gone is a positive from a fielding perspective, and a full season of Josh Naylor at first base and Brendan Donovan on the infield can only help.

Despite his Gold Glove credentials, though, it's an open question how much the Mariners are going to benefit from Donovan's presence.

The plan (at least for now) is to play him at third base, which is his best position in terms of DRS… but also one that he barely played in 2023 and 2024 and then not at all in 2025. His primary spot for the St. Louis Cardinals was at second base, where the Mariners are set to roll with Cole Young.

It's OK to be nervous about that. Despite only seeing about half a season's worth of action at the keystone in 2025, Young still posted a -9 OAA. That was the second-worst among all second basemen, beating out only Brandon Lowe.

If Young struggles this spring, that could be how the Mariners end up rolling with top prospect Colt Emerson, whether it's at second or third base. Yet while he's obviously a gifted defender at shortstop, he'd pretty much be learning on the job at the hot corner or the keystone.

Meanwhile, questions abound elsewhere. J.P. Crawford (-13) and Randy Arozarena (-5) were below water for OAA at shortstop and left field last year. Though Victor Robles is an above-average defender in right field — none of us has forgotten that catch in Houston — it isn't a given that he's going to play every day out there. A platoon situation would favor Luke Raley, who's more of a good bat than a good glove.

Can one buy that the Mariners will be better in the field this year than they were in 2025? Sure! It would be hard to be any worse, and the front office did address defense as if it was a problem with its offseason dealings.

Rather, what one hesitates to buy is that the Mariners will be a good defensive team. That's different from merely being a "better" defense, and there are still just too many question marks in the way of taking that leap.