Ranking best available free agent third basemen for Mariners after the 2024 season

The Mariners have quite a bit of work to do this winter. They wouldn't be overdoing things if they decided to rebuild their entire infield, but a particular point of focus should be the third base position. Seattle ranked 23rd in MLB for production from third base with a .643 OPS, primarily from Josh Rojas.

While Rojas was still a defensive asset, the front office would be remiss not to emphasize bats over gloves this offseason, especially given how poor the offense was in 2024. So who are some of the free agent candidates that could join the team on Opening Day?

As a preface, it should be noted that there aren't very many appealing options among primary third basemen. Gio Urshela was below replacement-level during his time with the Tigers and had a respectable late-season resurgence with the Braves, but there's a reason he has struggled to find a permanent home since being traded from the Yankees. Yoán Moncada had just 45 plate appearances in 2024 after being sidelined with an injury, but also hasn't been a plus bat since 2021.

Thus, most of the names on this list will be players who have experience at third base but may not be playing their primary position.

Ranking best available free agent third basemen for Mariners after the 2024 season

3. Miguel Rojas

This year's World Series showcased plenty of great talent, but one name was missing for much of the playoffs. Miguel Rojas was an underrated component of the Dodgers' core and ranked sixth in rWAR (3.4) while posting a 113 OPS+. He has an affordable $5 million club option, but given that he'll be nearly 36 and will spend his offseason recovering from an injury, the Dodgers may simply replace him with Tommy Edman and let him hit free agency. Rojas has primarily played shortstop in his career, but has always managed to squeeze in some third base reps.

Because of his current situation, Rojas would represent a band-aid solution to Seattle's problem at third base. It would be surprising for him to be signed for anything more than a year, but he would be a cheap and potentially productive option for the Mariners. There's a bit of reasonable skepticism about his seemingly anomalous impact in 2024 given his lackluster numbers from 2021-2023, but a lower defensive workload may allow him to continue his strong stretch at the plate.

2. Ha-Seong Kim

Kim has a team-friendly $7 million mutual option but it's unlikely that he'll uphold his end of the bargain given his outstanding tenure in San Diego. He has accumulated 15.3 rWAR over his four seasons and has been an exceptional infielder, cobbling together 48 Defensive Runs Saved since debuting in 2021.

He had a slight down year in 2024, posting a 96 OPS+, but his plate discipline numbers were still great. His chase rate (18.6%), whiff rate (15.9%), and walk rate (12.3%) were all in the top percentile of qualified hitters, while his strikeout rate of 16.4% wasn't too shabby either. His quality of contact numbers left a little to be desired but he still has pop when he needs it.

Kim is primarily a shortstop, but he's played 79 game at third base and mostly played second base in 2023. Perhaps the Mariners make him one of their larger expenditures, use him at third base for the next couple of seasons, and then shift him to the middle infield when needed later down the road.

1. Alex Bregman

Aside from the potentially high price tag, the most difficult thing about signing Alex Bregman will be having to support him after years of treating him as the team's most hated villain.

Regardless of one's feelings towards his attitudes and actions surrounding the 2017 sign-stealing scandal, it's undeniable that he is a productive player. Over the past three seasons with Houston, he has accumulated more than 2,000 plate appearances while slashing .260/.349/.449 for an OPS+ of 124 and 13.6 rWAR. Despite a somewhat slow start to his 2024, Bregman finished strong with a .947 OPS in August and an .810 OPS in September.

The financial obstacles to completing this deal shouldn't be overlooked. He'll be 31 by Opening Day and will be looking for a long-term deal, perhaps something similar to Nolan Arenado's nine-year, $275 million contract. Furthermore, despite reports of the Astros looking to reduce payroll in 2025, Bregman has been an integral piece of the team's core since being called up in 2016. Like Jose Altuve, Houston may make a concerted effort to ensure that Bregman only ever wears their jersey during his major-league career, especially if it means taking away a top talent from their division rival Mariners.

But if there was ever a time to spend on a position of need while shifting the balance of power in the division, Jerry Dipoto may not have a better opportunity.