New to third base, Polanco aims to stabilize Seattle's hot corner

PEORIA, Ariz. -- For the third time in four years, the Mariners will enter the regular season with a new outlook at third base, the position that had the most stability over the decade prior to this stretch while Kyle Seager manned the hot corner.

Seattle entered Spring Training with its primary plan centered on Jorge Polanco, who’s beginning to see more Cactus League reps at the position after easing into action following offseason surgery to repair the patellar tendon in his left knee.

Polanco started at third base for the second straight game in Wednesday’s matinee vs. the Royals, albeit after an off-day, and now that he’s been cleared to play there regularly, the Mariners intend to allocate as much playing time to him as they can -- especially given that it’s a mostly new position.

“His progression is such that he should be ready to go Opening Day, and that's what we're hoping for,” Mariners manager Dan Wilson said. “But there is a lot to learn. He's got a lot of things. It's a very different spot. Obviously, being on the other side of the infield, all the angles are different. But he's been doing it, and I think he's in a good spot.”

Polanco said that he’s still experiencing soreness in the knee immediately after games, but that the pain has subsided by the next day.

“I’m closer to 100 percent right now,” Polanco said. “I’m going to say that I’m kind of sore a little bit, but I’m going to start playing more just to get my confidence up. But it feels really close.”

Polanco is one of eight third basemen the Mariners have used this spring, but has seen the second-fewest innings there.

Among players in consideration for the Opening Day roster, Donovan Solano (26 innings) -- who was signed as a free agent to mostly play first base -- paces the group, and Miles Mastrobuoni (17 innings) is also in the mix. Prospect Ben Williamson (44 innings), who the club has said could contribute in 2025 but probably not at the outset, has seen the most action there.

Essentially, the Mariners are reaching go-time in Cactus play when it comes to deploying their starters more regularly -- but especially for Polanco, who came up as a shortstop with the Twins but has mostly played second base over the past four seasons, including last year in Seattle. He’s played 24 games at third over parts of 11 seasons.

Polanco returned to the Mariners on Feb. 3, via a one-year, $7 million contract that includes a $750,000 buyout on a vesting player option for 2026 -- after Seattle declined a $12 million club option and paid him a $750,000 buyout on Nov. 1. Polanco also had been linked to the Astros and Angels, among other teams.

The new deal was agreed to late enough in free agency that Polanco was among the few realistic options remaining for the Mariners to address their needs of adding multiple infielders within their budget -- the other being Solano, who signed a one-year, $3.5 million contract on Jan. 13.

“I had a couple opportunities and other teams that wanted me,” Polanco said. “But in the end, I made the decision to come back here. I feel like that was the best decision that I could make.”

The Mariners are banking on a bounceback from Polanco as he enters his age-31 season. Beyond the knee issue, for which the need for surgery became clear around the All-Star break, he also missed nearly one month in the first half with a right hamstring strain. Both injuries significantly impacted his swing and could’ve been a correlation to a 29.2% strikeout rate (up from a career 18.2% entering ‘24) and a .651 OPS (down from a career .780).

“He's out there getting booed,” Mariners president of baseball operations Jerry Dipoto said. “He's running the highest strikeout rate he's ever had in his career, and he couldn't get his swing loaded. And if you can't get your swing loaded, and you were primarily a fly ball [and] line hitter ... a lot of those balls are going to come up shorter.”

Overall, Polanco slashed .213/.296/.355 with 16 homers in 2024, though he was far more consistent in the second half (114 wRC+, where league average is 100) than the first (71 wRC+). Like much of the Mariners’ ambitions with their offense entering 2025, they’re hoping that Polanco’s finish last season is far more telling to his future outlook than his start.