Brendan Donovan has had about as good a start as he could have with the Seattle Mariners. While the stars in the middle of the lineup have been among the worst in the league, it has been Donovan and the hitters at the bottom of the order who have carried this offense through seven games. Although the sample size is small, Donovan looks as advertised since his trade to Seattle this offseason and profiles as a core player for a team with World Series aspirations.
Yet despite leading all third basemen with 0.6 WAR early in the 2026 season, questions are already emerging about how long he will remain at the hot corner.
How Long Will Brendan Donovan Remain at Third Base?
Defensive Issues
Despite his success at the plate, the transition to third base has been tougher than the Mariners may have anticipated. Fielding metrics are often difficult to rely on, especially with such a small sample size, but dropped balls, inaccurate throws, and a lack of range have all shown up through the first series, with some costly errors hurting the Mariners. In one sequence, a charge at third turned into an extended inning after an errant throw to first, leading directly to runs that cost them the game against the Cleveland Guardians.
Brendan Donovan throws the ball into right field and the Guardians take the lead back pic.twitter.com/lDdwcvCpkO
— Talkin’ Baseball (@TalkinBaseball_) March 29, 2026
The switch to the hot corner for a second baseman was always going to be challenging, as throwing from the other side of the infield requires a steeper learning curve. This could be fixed with more reps, and there is less long-term concern than there is in the short term. However, the issue for the Donovan third base experiment is that his successor may already be waiting in the wings.
An Accelerated Succession Plan?
Following Colt Emerson’s eight-year extension, noise around his call-up to the major league roster feels inevitable. He has already been getting reps at third base, making some impressive plays, and shifting from shortstop to third is generally an easier transition than moving from second. Jerry Dipoto also confirmed that with J.P. Crawford reinstated to the 26-man roster, he will be the everyday shortstop in 2026, meaning any playing time for Emerson will likely come at third this season.
Colt Emerson having a very good defensive game at 3B. pic.twitter.com/y2Qao2KtCn
— Mariners Minors (@MiLBMariners) April 1, 2026
The Mariners have extremely high expectations for Emerson, who has the ceiling of a 6 WAR shortstop at the major league level. They will want to integrate him as soon as possible and clearly believe he is ready to make the jump.
It appears to be a matter of when, not if, Emerson is promoted to the major league roster. When that happens, the question becomes how the Mariners accommodate Donovan, their leadoff hitter. A move to right field seems the most likely outcome, which would mean Luke Raley sharing DH duties with Dominic Canzone. However, this currently appears unlikely, as both players are not only among the most in-form hitters in the lineup but also two of the most productive hitters in baseball.
The more realistic outcome may be that the Mariners look to maximize Donovan’s flexibility, using him in a utility role to fill gaps across the outfield, third base, or DH, depending on the situation.
There is Still Time
There is speculation that Emerson’s extension means the writing is already on the wall for Donovan. However, any major roster change involving Emerson is more likely to take place around the All-Star break. Since Emerson has signed his extension, he is no longer eligible for Rookie of the Year and, subsequently, the draft pick incentives, meaning there is no urgency to promote him early. The Mariners can allow him to continue building reps at third base.
Additionally, the knock-on effect of moving Donovan to right field would push one of the two in-form hitters out of the lineup. Given how well Raley and Canzone are performing, this is not a move that benefits the team right now.
Donovan has quickly established himself as a vital part of the lineup, but if his defensive struggles at third continue, Emerson’s pathway could accelerate. The Mariners do not need to make an immediate decision, but one is clearly coming. With multiple left-handed bats competing for playing time, how Jerry Dipoto and Dan Wilson manage that balance could become a defining factor in shaping this roster as the season develops.
Main Photo Credit: © Steven Bisig-Imagn Images
