4 controversial trades the Mariners must consider in 2025-26 MLB offseason

In recent years, being a fan of the Seattle Mariners has meant never really knowing when a controversial trade might come. One minute, things are fine. And then the next, there goes a Kendall Graveman, a Paul Sewald or a Eugenio Suárez.

It has us thinking who might be next in the 2025-26 MLB offseason. The answer may prove to be nobody, but president of baseball operations Jerry Dipoto wouldn't be doing his job if he didn't at least kick the tires on various deals.

With this in mind, here are four Mariners who nobody wants to see leave Seattle, but who perhaps should be moved if the offer is right. They are ranked in order from what would be the smallest surprise to what would be the biggest.

4 players the Mariners should consider moving in controversial trades

4. RHP Luis Castillo

Castillo had a better year in 2025 than he did in 2024, pitching 5.1 more innings and lowering his ERA from 3.64 to 3.54. If he can come through with more of the same, his $24.15 million salaries for 2026 and 2027 would be money well spent.

Yet Castillo is 32 years old, and his age is really starting to show in his fastball velocity and strikeout rate, both of which are declining. The Mariners were willing to listen on him last winter, and you have to figure they will again this offseason.

He would have to waive his no-trade clause for a deal to happen, but any trade Seattle makes could be worth it for the salary relief alone. There are going to be major holes to fill this winter, including as many as three in the lineup if Jorge Polanco declines his player option and becomes a free agent alongside Josh Naylor and Eugenio Suárez.

3. C Harry Ford

Ford was mentioned so many times as a trade candidate this year that it became a broken-record thing. Yet in the end, he stayed put and even made it onto the playoff roster after getting called up for a cup of coffee in September.

Even with the Mariners set to move on from Mitch Garver this offseason, it's still fair to ask if Ford's best role is as Cal Raleigh's catching partner. That would make him a reserve, and a role like that would arguably be wasted on a 22-year-old who ranks as MLB Pipeline's No. 42 prospect.

Ford may have more value as a trade chip, especially if he could bring back an impact bat to fill one of the aforementioned holes.

2. LF Randy Arozarena

The trade that Dipoto made for Arozarena in 2024 deserves to be counted among his greatest wins. His 214 games as a Mariner have yielded 32 home runs and 35 stolen bases, plus an All-Star selection this year.

It'll cost the Mariners to keep the 30-year-old around, however. Per Steve Adams of MLB Trade Rumors, he's due for a raise from $11.3 million in 2025 to $18.2 million in 2026 via arbitration. On this year's team, that would have made him the third-most expensive player after Castillo and Julio Rodríguez.

Given that Arozarena is a streaky hitter who can be unpredictable in the outfield, the Mariners may be better off shipping him elsewhere and using that $18.2 million to fill other needs.

1. RHP Logan Gilbert

Trade Logan Gilbert? Heck, it was only earlier this year that he seemed like the next candidate for an extension after Julio and Raleigh.

Cut to now, though, and his status with the franchise seems less certain. He'll certainly be tendered a contract for a projected salary of $10 million, but he would then face pressure to bounce back in 2026. He missed time with a forearm strain this year, which contributed to him ceding his role as the Mariners' ace to Bryan Woo.

Gilbert is 28 and controlled through 2027, making him older and less controllable than Woo, George Kirby and Bryce Miller. As the latter two crushed their trade value with down years, Gilbert is the most sensible candidate to go if Dipoto gets a chance to leverage his surplus of arms for a bat in a trade.