Sea Level 2025/2026 Mariners Offseason Guide

40 player profiles complete with fit and cost analysis, the 2025/2026 Seattle Mariners Offseason Guide is here.

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The Mariners were just eight outs away from their first World Series appearance in franchise history just a few weeks ago. Back in 2022 I came on this website and declared that the Mariners were here to stay, and that their 2022 run was just the beginning of what should be a large contention window for this franchise. It took three whole years to get another crack at October, and this time they were even closer to a destination that continues to elude this franchise. That needs to motivate them now more than ever. It can’t be three more years before they taste champagne and cigar smoke.

The time is now to act, and the pressure shifts to the front office group to get the job done this offseason. Ownership declared their support (we will see on that one), putting the pressure on Jerry Dipoto, Justin Hollander and this front office group to tackle a the offseason roster building task that has been a massive obstacle. These Seattle Mariners have a core of players that is championship caliber. They showed it this year, coming to the doorstep of a frontier this franchise has never seen. Seattle still has holes. Josh Naylor, Jorge Polanco and Eugenio Suarez have all hit the market. Question marks loom large in this position player group and this roster in general, and that is what we try to tackle in the 2025/2026 Sea Level Offseason Guide.

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Needs

A lot of people have intimated that the Mariners will be an improved team in 2025, a team that will naturally improve. I don’t know if I agree with that statement unless they add players to get legitimately better.

The Mariners are almost in the exact same spot roster wise that they were last winter, with holes at first base, third base, designated hitter, and question marks in right field and at second base. Their rotation ended the year healthy, but performance and health concerns were littered throughout the year. The bullpen was solid, but was heavily relied upon which can create issues the following season with performance and availability.

Seattle doesn’t need to fill all of those spots, but needs to fill several of the following

-First Base: This is the only non negotiable of any of the needs. Seattle needs a first base option. They don’t have one in house and there isn’t one close to the big leagues.

-DH: Seattle lucked their way into their best DH season since Nelson Cruz by signing Jorge Polanco to play third base. They need to add a DH or an outfielder to put Canzone there.

-Third Base- Seattle could opt to roll with Ben Williamson+ a utility type until top prospect Colt Emerson is ready to go, or they could go out and fill the need with an Alec Bohm type. Either way, if they are going to leave this spot up to Williamson they better add bats elsewhere.

-Relievers: One of them would preferably be left handed to help ease the workload of Gabe Speier, but the Mariners really need to add some proven depth to this group to take the workload off of the leverage group.

-Leadoff type: The Mariners probably shouldn’t go into next season slotted with Randy Arozarena or Julio Rodríguez as their leadoff hitter. They could really use a leadoff type this offseason, and that might have to come outside of pursuits to retain Naylor and Polanco.

-Starting Pitcher: This may be a need, or it may not. While Castillo is the most likely, the Mariners are at an interesting crossroads where they could realistically deal any of their starters aside from Bryan Woo. If they do, they need to backfill with depth or impact while waiting for Kade Anderson and Jurrangelo Cijinte.

Bats

Josh Naylor

Josh Naylor became a beloved player in Seattle in just two short months, and the fanbase is essentially throwing themselves at the 28-year-old free agent first baseman. It is for good reason. Naylor is a perfect fit in so many ways.

He makes a ton of contact, plays a position that Seattle has no other options at, and brings a certain intensity and baseball IQ that this group needed. Naylor truly changed the team with his presence and ability to drive in runs.

The Mariners have stated it is a “priority” to bring Naylor back, but to what extent they would be willing to go is unknown. It seemed like Naylor enjoyed his time in Seattle, but It is also very possible that the first baseman is inclined to look at opportunities on the East Coast, closer to the home of him and his high school sweetheart with whom he recently celebrated the birth of their first child. Somewhere between 4-80 and 5-115 million probably gets this done, but as of right now I don’t know if I see a return in the cards with Boston, New York, and others looming. Seattle would be wise to cast a wide net and not pigeonhole itself into Naylor being their only option. With all of that being said, Josh Naylor is the best fit of any player on the market that is available.

Team Fit: High

Cost: High

Jorge Polanco

While Naylor is certainly the best fit, you could argue a reunion with Polanco is a close second. The 32-year-old second base/DH experienced renewed health in 2025 and posted a 132 wRC+ while cutting his strikeout rate in half! He carried the offense at times throughout the season, including a magical trip through the ALDS.

Polanco seems to be the type of player who may want to return to a place where he is comfortable, and I do think in this situation Seattle will have a leg up. He could slot in as the primary DH and fill in at second base periodically, and even potentially learn some first base to help preserve his body and fill a need for Seattle if they don’t re-sign Josh Naylor.

Multiple people have speculated that Polanco’s deal to look something like the one Mitch Garver signed with Seattle a few years ago. That, or the Mitch Haniger deal with San Francisco, would be good comps for Polo (12-15 AAV). I think there’s a solid chance he’s back in Seattle as the primary DH next year.

Team Fit: High

Cost: Medium

Eugenio Suárez

The trade to bring Good Vibes Only home to Seattle was a fun story and moment in Mariners fandom. Geno’s return to Seattle brought an energy that outpaced his production on the field, and while he will always be beloved, he will probably be looking for a new home in 2026. Suárez struggled mightily in the second half, specifically in T-Mobile Park. If it isn’t a one-year deal, I can’t see Seattle bringing him back.

Geno will probably want multiple years, as this may be the last time he can capitalize on a multi-year deal before he retires. I certainly wouldn’t mind a one or a two year deal in Seattle to play either corner spot, but I can’t see it.

Team Fit: Medium

Cost: High/Medium

Mitch Garver

Look, I get it, the contract didn’t work out the way Seattle wanted it to. But if Garver is comfortable in the Pacific Northwest and is okay being a backup catcher at this point in his career, a return to the Mariners as a backup makes a lot of sense. At this point I’d think Harry Ford will be the backup, but if he is dealt Garver makes a ton of sense.

Team Fit: Medium

Cost: Low

Bats

Kazuma Okamoto

Okamoto is probably my favorite backup plan to Josh Naylor out there. While most fans will focus on Naylor, and some more optimistic fans will convince themselves they are interested in Murakami, Okamoto might be the most likely option out of the group. While he doesn’t come without warts, Okamoto is a solid player who could fit nicely on Seattle’s roster.

Okamoto has spent time at first and third base in his pro career, but the 30 year old will likely find himself at first base in the MLB. He missed time in 2025 due to an elbow injury but still posted solid numbers, slashing .327/.416/.598. This is somewhat comparable to his overall numbers in the NPB, where he has hit 248 home runs and slashed .277/.361/.521.

Many have questions about swing and miss with the elevated fastball velocity at the major league level, but Okamoto has never struggled with making contact against fastballs or contact in general, striking out just 11 percent of the time last year. He also did this a few years ago against a 99 MPH heater from Roki Sasaki.

I really like the idea of Okamoto as a solid backup option to Josh Naylor. His contract projection is similar to Naylor’s, but Okamoto can play third base at a decent level as well. The Mariners should still favor Naylor but Okamoto is an intriguing backup option.

Team Fit: High

Cost: High