The Seattle Mariners appear to be closing in on a significant move - one that could reshape their infield and add a key left-handed bat to the lineup. According to multiple reports, Seattle is working toward a three-team trade that would bring in All-Star infielder/outfielder Brendan Donovan from the St. Louis Cardinals, with the Tampa Bay Rays also involved in the deal.
This is a move that’s been in the works for weeks, and now it seems to be on the verge of crossing the finish line. Donovan, 28, would bring a rare blend of contact hitting, defensive versatility, and postseason experience to a Mariners team that came within a game of the World Series last fall.
Donovan’s Fit in Seattle
Let’s start with what Donovan brings to the table. He’s not the flashiest name on the market, but he’s exactly the kind of player who can elevate a roster - the type of glue guy contending teams covet.
In 2025, Donovan slashed .287/.353/.422 with 10 home runs, 32 doubles, and a .775 OPS across 118 games. That’s not just solid production - it’s reliable, consistent offense from the left side of the plate. In an era where strikeouts are up and batting averages are down, Donovan’s high-contact approach stands out.
Defensively, he’s one of the most flexible players in the game. He played 100 games at second base last season but also saw time in left field (18 games), shortstop (6), and has previous experience at first, third, and even right field. This isn’t just a guy who can “fill in” - he’s a true utility weapon who can start at multiple spots and hold his own.
Donovan was a Gold Glove winner at the utility position as a rookie in 2022 and earned his first All-Star nod in 2025. He’s also under team control through 2027 and will earn $5.8 million this season after avoiding arbitration. That’s a team-friendly deal for a player who could have a major impact on both sides of the ball.
What Seattle Is Giving Up
While the full details of the trade haven’t been finalized publicly, reports indicate that third baseman Ben Williamson is expected to head to Tampa Bay as part of the three-team package. Williamson, a promising young infielder, has shown upside but was likely blocked in Seattle’s current infield picture. Moving him in a deal for a proven, versatile bat like Donovan makes sense - especially for a team looking to win now.
Dipoto Hinted at This Move
Mariners president of baseball operations Jerry Dipoto had already teased that another addition was coming. Speaking at Seattle’s FanFest over the weekend, Dipoto said, “I do think there is one more player that is coming along for the ride that is not in a Mariners uniform just yet.”
Now we know who he was talking about - and why the front office was so focused on finishing this deal.
What This Means for the Mariners’ Lineup
Adding Donovan gives Seattle the flexibility to mix and match around the infield without putting too much pressure on their younger players. He can slot in at second, fill in at third, or even spend time in the outfield depending on how the roster shakes out. That kind of versatility is invaluable over a 162-game season.
It also helps balance out a lineup that leaned right-handed last year. Donovan’s lefty bat gives manager Scott Servais more options, particularly against tough right-handed pitching.
And let’s not overlook the timing. This comes just days after the Giants signed Luis Arráez and the Reds brought back Eugenio Suárez - two other infielders who had been on the move this offseason. The market was shifting, and Seattle made sure they didn’t miss out.
A Busy Offseason in Seattle
This would mark the second major trade of the Mariners’ offseason. Back in December, they shipped top prospect Harry Ford (MLB’s No. 42 overall) and minor league pitcher Isaac Lyon to the Nationals in exchange for left-handed reliever Jose Ferrer - a move aimed at bolstering the bullpen.
In free agency, Seattle re-signed first baseman Josh Naylor and added veteran outfielder Rob Refsnyder and backup catcher Andrew Knizner. None of those moves were headline-grabbers on their own, but together, they reflect a team intent on building depth and flexibility - and now, with Donovan potentially in the fold, the Mariners are taking a clear step forward.
Final Thoughts
If the deal goes through as expected, Brendan Donovan won’t just be another name on the roster - he’ll be a key piece in Seattle’s push to get over the hump in 2026. After coming within one win of the World Series last year, the Mariners are clearly operating with urgency. And in Donovan, they may have found the kind of all-around contributor who can help them finish the job.