Mariners defense is doing the exact opposite of what was expected in 2026

So far, the Mariners have been a tough watch. At 4-9, Seattle currently has the worst winning percentage of any MLB team and their recent slew of underwhelming outings has been a major cause for concern.

This year was meant to be different, but the team has somehow fallen back into old habits, allowing a sagging offense to drag down a stellar pitching staff. Unfortunately, the bats aren't the only problem.

Despite optimistic projections, the Mariners have some of the worst defensive results of 2026

In an article for MLB.com about each team's defensive outlook heading into 2026, Mike Petriello predicted that Seattle would take a meaningful step forward when it came to their fielding production thanks to the departure of below-average defenders like Jorge Polanco and Dylan Moore and addition of players like Josh Naylor and Brendan Donovan. It was a sensible forecast at the time, but the results after two weeks point in the opposite direction.

The Mariners have accumulated -5 Outs Above Average thus far, 29th in MLB, with Randy Arozarena (-2) and Brendan Donovan (-3) having most negative impact on the team. Arozarena has placed in the bottom quartile of OAA every season since 2023 while Donovan, despite being a Gold Glove winner, is playing a relatively new position in third base. Neither player is helping the situation, but they're far from the only ones making mistakes in the field.

Still, there may be a silver lining. Defensive Runs Saved is a different metric often used to gauge a player or team's defense and the Mariners grade out far better by that metric, placing sixth in MLB with 10 DRS. Cole Young leads the team in DRS just as he does for OAA, but Rob Refsnyder already has two DRS despite spending just 10 innings in the field.

Like most statistics in baseball, defensive metrics need larger samples to really be meaningful. It's already an aspect of the sport that can vary significantly from year to year so, coming to a conclusion after two weeks of games could seem premature, but every win matters and could be the difference between a playoff berth and an October spent at home.

If the Mariners aren't able to figure it out at the plate, they'll need to optimize their run prevention unit to give themselves a chance at turning things around soon. This may take the form of switching positions or even calling up Colt Emerson. Whatever they're going to do, they'll have to do it fast before things really coming off the rails.