Looking At The Mariners’ Internal Infield Options

Mariners’ current infield picture

At the end of the 2025 season, Seattle lost three infielders to free agency: Josh Naylor, Jorge Polanco and Eugenio Suárez, leaving J.P. Crawford as the only clear infield lock for 2026. The club quickly brought Naylor back on a five-year deal to stabilize first base going forward.

Former early draft picks

Cole Young is a former first-round pick, selected 21st overall by Seattle in 2022, and he now looms as a key internal candidate for second base. The Mariners also used the 22nd overall pick in 2023 on Colt Emerson, who surged through three minor league levels in 2025 and firmly entered their near-term plans.

Colt Emerson’s rapid rise

In 2025, Emerson logged time at High-A, Double-A and Triple-A, totaling roughly 600 plate appearances and producing strong on-base skills, extra-base power and above-average overall offensive output. He primarily played shortstop with some third base, and is now viewed as a consensus top-15 prospect in the league despite being only about 20 years old with limited Triple-A experience.

Path to the 2026 roster

Seattle appears open to the idea of carrying Emerson on the Opening Day roster because clubs are now more willing to promote elite prospects immediately due to prospect promotion incentives. The team previously did this with Julio Rodríguez in 2022, and his Rookie of the Year award ultimately earned them an extra 2023 draft pick that they used on outfielder Jonny Farmelo.

Shortstop and third base picture

Crawford is currently locked in as the starting shortstop for 2026, but he is scheduled to reach free agency after that season. In the near term, Emerson could break in at third base, with the possibility of sliding over to shortstop if Crawford departs.

Second base competition

Second base shapes up as a competition among internal options such as Young, Blake Bliss and Felnin Celesten/Arroyo (depending on exact roster composition in the piece). The front office could leave the position open in spring training and hope that at least one of these young infielders takes a clear step forward and claims the job.

Defense-first fallback options

If Emerson is not ready or struggles defensively at third base in the spring, Seattle has glove-first options like Ryan Williamson who can provide a steady infield floor. This kind of profile gives the Mariners a safety net while still allowing them to gamble on upside from younger bats.

Utility infield depth

Leo Rivas

Leo Rivas projects more as a part-time or bench piece than as a regular. He is known for drawing walks, offering defensive versatility across second, short, third and the outfield corners, but he has limited power, and he still has a minor league option remaining.

Miles Mastrobuoni

Miles Mastrobuoni has a similar minor league profile built on versatility and on-base ability, but he has not produced at the plate in his major league opportunities. He is now out of options, which makes his roster spot more precarious if he does not hit.

Samad Taylor

Samad Taylor fits the same general bucket of flexible utility depth who can move around the diamond and potentially the outfield. Like Rivas and Mastrobuoni, he is more of a role player candidate than a projected everyday infielder.

External additions still in play

Despite these internal candidates, the article suggests that adding established big league infielders remains an appealing path. Veterans such as Polanco, Suárez or similar free agents could stabilize the infield if the young options do not immediately seize everyday roles.

Brendan Donovan as a target

A trade or signing for Brendan Donovan is highlighted as a particularly logical fit because of his defensive flexibility. Donovan could handle second or third base if prospects like Young or Emerson fall short, and if they succeed, he could slide into corner infield or even corner outfield work.

Other free-agent possibilities

The designated hitter spot is relatively open, which gives Seattle room to juggle bats between DH and the corners. Free agents such as Willi Castro or Amed Rosario are mentioned as less exciting but still viable utility-type additions compared with a higher-end target like Donovan.

Overall roster strategy

The Mariners appear to be balancing two goals: giving internal prospects a real shot at everyday work while maintaining enough veteran depth not to depend entirely on young players. The strength and timing of Emerson’s and Young’s development will likely determine how aggressive the club needs to be in pursuing external infield help.

The team’s internal infield mix blends high-upside prospects like Emerson and Young with versatile depth options such as Rivas, Mastrobuoni and Taylor, while veteran additions remain firmly on the table.

Author’s brief summary

Seattle’s infield outlook hinges on whether top prospects Emerson and Young can claim everyday roles in 2026, allowing the club to rely less on stopgap veterans and more on its emerging core.

MLB Trade Rumors — 2025-11-28