Seattle Mariners 2025-2026 Offseason Wishlist

You could make a case for every team in baseball needing to improve its bullpen. No matter where you look, there’s going to be at least a spot or two open in most bullpens, but Seattle’s need is more significant than most.

Andrés Muñoz has been one of the better back-end arms for a couple of years. A slider with a 51% whiff rate combined with an upper-90s fastball produces the type of swing-and-miss stuff you need out of a closer. That box is checked.

Combine Muñoz with Matt Brash, who has a slider that ends up on highlight reels, and you have a one-two that can shorten games and give the Mariners high-leverage innings.

However, the options start to run thin quickly. Gabe Speier has been one of the more underrated lefties in the game, and Eduard Bazardo showed enough to be a legit option, but the fall-off after those four is significant.

Seattle needs to add multiple relievers, but I think a high-end option should be in play. They can afford the luxury of adding another high-leverage reliever, especially when the team is returning most of its talent from last season.

Free Agent Options: Nick Martinez, Danny Coulombe (L), Mike Soroka, Sean Newcomb (L)

Martinez did not match his 2024 numbers but still had a decent season in 2025. His versatility, being able to jump from the rotation to the bullpen, would give the Mariners some flexibility and insurance in multiple spots. Soroka fits a similar role, but I’d rather have him transition fully to one-inning stints. He could fill a middle relief role with upside and added swing and miss.

The two lefties are both veterans, with Coulmbe having more sustained success than Newcomb. I doubt either will demand much term, and both would be significant upgrades to what the second lefty has offered recently in the Mariners bullpen.

Improve at Third Base

Bringing back Eugenio Suárez was a band-aid, but not a long-term fix. I’m not so sure that the Mariners are going to find their long-term fix at third this winter, either. The free agent market outside of Alex Bregman (and Suárez) comes with plenty of concerns, both short and long-term.

Ben Williamson doesn’t exactly excite many, and Jorge Polanco will have suitors elsewhere even if another deal to return to Seattle is on the table. In fact, I don’t think the Mariners will want to give Polanco the type of deal he could get elsewhere, and ultimately, they will need to find a different solution.

Possible Free Agents: Munetaka Murakami, Ha-Seong Kim, Yoán Moncada

Murakami would be by far the biggest splash I could see the Mariners making at third. The 25-year-old is coming over from Japan and would add another power threat from the left side. His struggles with velocity have been well documented, but it’s worth noting that players in Japan do not see as much velocity, so one could hope improvement is possible with time on task.

Ha-Seong Kim is a great fit in Seattle. A plus defender and high-floor bat that can play short and second at a high level would give the Mariners some options. If a different third baseman comes along, now or throughout his contract, Kim would become insurance to Cole Young and Colt Emerson up the middle. A steady presence that would fill out the bottom third of the lineup nicely.

Moncada’s story isn’t all that different from Polanco’s when he joined Seattle: a switch-hitter with some success and a history of injuries. Polanco is the better player, but Moncada is a cheaper solution.

Potential Trade Targets: Nolan Arenado, Alec Bohm

Okay, let me be clear. Neither of these players is going to get Seattle fans jumping for joy. Sometimes, all you need is a higher-floor player to help round out a lineup, and both of these names can give you that.

If the Cardinals eat a significant portion of the salary, Arenado would be a great fit. I think he’d waive his no-trade clause to join a true contender like the Mariners, as well.

He still makes great contact, and I think there’s a path for him to stop selling out for power as much and transition into more of a bat-to-ball hitter with plus defense, which is a similar profile to Bohm (though the latter’s defense is worse).

Add to the Bench

The offseason is a time to dream about the best-case scenario: high-end, future Hall of Famers joining your team. Well, more often than not, that dream fails to come true. What happens more often is your favorite team signs a player(s) that helps improve the lineup depth and even the bench.

Although not sexy, we all know how important depth can be. For a team like the Mariners, who have a young and unproven second baseman, a hole at third, and a lack of backup outfielders, adding depth will be crucial.

I’m all for Harry Ford and Cole Young playing fairly big roles on this team; give the young talent a chance to raise the ceiling of the roster. However, plan B needs to be just as important. The Mariners are too good to hope youngsters figure it out, and if not, veteran bench players get to fill in.

Potential Free Agent Fits: Luis Rengifo, Willi Castro, Ramón Urías, Mike Tauchman

Luis Rengifo is a name Seattle fans know well from his time with the Angels. He’s a switch-hitter who can play all over, puts the ball in play, and has some speed, but is coming off a horrible season. A one-year, prove-it deal while selling him on the idea of potentially seeing increased time at third is a risk worth taking.

Urías is another veteran who has been a solid bat, especially against lefties. His versatility is limited to the infield, but he is a high-floor bench player. The type of player that won’t fall off a cliff but also isn’t going to be mistaken for an All-Star.

Perhaps the best of the bunch is Castro, a switch-hitter who has tons of experience literally all over the field. The numbers took a nosedive once he landed with the Cubs at the deadline, but I’d be willing to bet on a bounce back.

Lastly, Tauchman. Who doesn’t love a veteran outfielder who puts up great at-bats? Nothing flashy or high-end, but another sneaky good player who should not cost too much.

Extend From Within

As much as we all love talking about adding, sometimes the best money spent in the offseason is on your own players. Too often, teams try to force fits and shell out extra money to entice a player to join their team when the money could have been better spent on the players they already have a ton of insight on.

The Mariners have shown an ability to successfully identify which players in their organization are worthy of locking up long-term, such as Julio Rodríguez, Cal Raleigh, Andrés Muñoz, Luis Castillo, and J.P. Crawford.

As you know, these types of deals are usually an exchange of more money now for additional years in what would be a player’s free agency. Sometimes they work, sometimes they don’t. But, like I said, the players you have the most insight on are the ones in your building every day. Investing in the right ones can be as much of an offseason victory as signing free agents.

Bryan Woo and Logan Gilbert are set to become free agents after next season. George Kirby after 2028 and Randy Arozarena after this coming season. The M’s could also consider the likes of Colt Emerson, Cole Young, and Harry Ford for “prospect” extensions.

I could make a case for Seattle to extend any of these players, and I’m sure Mariners fans would be excited if any received an extension today. However, the number one focus should be on pitching, and my personal choice would be Gilbert.

Gilbert is an ace and true workhorse of this rotation. Not only is he a career 3.58 ERA/3.52 FIP pitcher, but he’s about as consistent as they come. At 28 years old, he should still have a number of years left in his arm. You don’t get pitchers of Gilbert’s caliber all that often, and the M’s should do all they can to keep him around.

Final Thoughts

Losing Suárez and Polanco will be impactful, but both are possible to replace. All things considered, the Mariners are returning a large portion of their production and should be right back in World Series contention in 2026.

They are at a point in their team life cycle where adding is a must. I’d love to see them make the huge splash move that changes the trajectory of their team, but that’s not the only way to get where they want to go.

Surrounding their high-end talent with a number of above-average regulars, boosting the bullpen, and giving their top prospects a runway would make this team dangerous.