5 burning questions hanging over Mariners' 2026 spring training

Spring training games are officially underway, giving the Mariners and their fans the first taste of live baseball in months. For tenured big leaguers, this is a chance to get warm before the season officially starts next month. For those on the cusp of snagging a coveted roster spot or making their debut, it's a chance to strut their stuff.

Although none of the results will count for much on paper, each organization is paying careful attention to the data because it will ultimately help them find answers to some of the questions that still linger. The Mariners are slated to be a serious postseason contender, but that doesn't mean they don't have a few uncertainties of their own.

These are the 5 burning questions the Mariners must answer in spring training

How will the infield look with Brendan Donovan, Cole Young, Colt Emerson, and any other dark horse candidates?

Seattle's acquisition of Brendan Donovan was a perfect way to bookend the offseason, but it didn't plug the infield holes as cleanly as some may have expected. Because the Mariners lost both Eugenio Suárez and Jorge Polanco in the offseason, they didn't have any compelling starters at second or third base. Furthermore, Ben Williamson, an internal favorite to start at the hot corner, was included in the three-team deal to bring Donovan to Seattle in the first place.

Donovan is currently slated to play third base, which would give Emerson and Young opportunities to play second base. It's a sensible decision given than it's a more natural fit based on their experience and skillsets. However, despite the impressive reputation of both prospects, neither is proven at the major league level just yet. The team also has Miles Mastrobuoni and Ryan Bliss, who now seems like a complete afterthought.

Any way you slice it, Seattle has plenty of options. They'll just have to play around with different defensive alignments and lineup permutations before they're able to find the right fit.

What will the rest of the bullpen look like?

Unlike many teams, Seattle actually has a strong core of relievers outside of just their closer. Matt Brash, Gabe Speier, and new trade pickup Jose A. Ferrer bring plenty to the table. The Mariners will also be bringing back other medium leverage arms like Eduard Bazardo, Carlos Vargas, and Casey Legumina, but there's still room for a few more.

The organization hasn't stopped picking up pitchers with potential, but none of the recently acquired relievers are clearly finished products ready to toe the slab for a team with World Series aspirations. The remaining veterans on the free agent market leave little to be desired so outside of a trade, the Mariners could end up depending on some of the young talent in their farm system just waiting to break out.

Will participation in the WBC impact the roster positively or negatively?

Participation in this year's World Baseball Classic has been a mixed bag. This year's installment seems to be reaching a fever pitch in terms of fan hype, but organizations are far less excited about it. Several superstars, including Francisco Lindor, Carlos Correa, and most recently José Alvarado, are being kept out of the tournament due to insurance concerns.

The Mariners' biggest superstars are all competing which could swing either way. It could be the early start that guys like Julio Rodríguez need to hit the ground running for the regular season. It could also lead to serious harm and missed games like it did for Jose Altuve and Edwin Díaz in 2023. It may be a point of national pride for spectators but for MLB teams, it's a visit to the injured list just waiting to happen.

Will Raley and/or Robles bounce back?

Víctor Robles may have set an unfair standard for himself during his first season in Seattle. It took him just half a season to accumulate 3.1 rWAR and the front office didn't waste time extending him. Unfortunately, he failed to live up to the hype last season. With last season's frustrations and injuries behind him, hopefully he can return to being as great as he was in 2024.

In a similar vein, Luke Raley also failed to follow up a successful 2024 with an equally productive 2025. Some of this could be attributed to injury and positional uncertainty as he spent most of his time starting intermittently and splitting time between the outfield and first base. Nonetheless, with more talent on the team than ever before, like Robles, he'll have to prove that he deserves a spot on the roster.

Who will be the breakout prospect?

It's difficult to pick the most valuable asset in a stacked farm system like Seattle's, but there are a few leading candidates. Colt Emerson (No. 9 prospect in MLB) is the consensus favorite but he isn't the only one that could rocket up the ranks. Kade Anderson and Ryan Sloan both have the potential to be top arms at the minor league level while position players Lazaro Montes, Michael Arroyo, and Jonny Farmelo bring their own upside to the table.

Things could change if the Mariners decide to call up one or some of these names, graduating them from prospect status. Even if they do so, it seems like they've found a way to have a never-ending supply of exceptional talent. Regardless of who seizes the mantle, you can be sure that someone just as promising will be there to take their place once they get called up.