Details On Mariners/Red Sox Trade Talks

The Mariners and Red Sox have been linked together in trade rumors for the better part of a year, including reports from earlier this winter that Seattle turned down Boston’s offer of Triston Casas for either Bryan Woo or Bryce Miller.  Another intriguing deal involving Casas was at least discussed between the two sides, as MLB.com’s Mark Feinsand reports that the Sox weren’t willing to agree to a deal that would’ve seen Casas swapped in exchange for Luis Castillo.  The Red Sox were only open to such a trade if Masataka Yoshida was included along with Casas.

Yoshida signed a five-year, $90MM deal with the Red Sox in December 2022, back when Chaim Bloom was still Boston’s chief baseball officer.  The contract greatly exceeded what Yoshida was expected to land in his entry into North American baseball, and once Craig Breslow took over Boston’s front office last winter, it didn’t take long before Yoshida’s name began to surface in trade rumors.  Yoshida is still owed $54MM over the final three seasons of that deal, plus he underwent shoulder surgery in October, though he is expected to be recovered in time for Opening Day.

Since Yoshida’s contract has become the central talking point of his MLB career, his salary tends to obscure the fact that he has posted decent numbers over his two seasons in the Show.  Yoshida has hit .285/.343/.433 and 25 home runs over 1001 plate appearances, translating to a 112 wRC+.  That production has ticked upwards against right-handed pitching, as the lefty-swinging Yoshida naturally has better splits against righties (.810 OPS in 749 PA) than lefties (252 PA).  Known for being a very disciplined hitter during his time in Japan, Yoshida has been one of baseball’s toughest batters to strike out during his time with the Red Sox.

For all of Yoshida’s contact, however, he hasn’t delivered much in the way of hard contact or power numbers.  He has also posted subpar walk rates, and public defensive metrics didn’t like his glovework over 713 1/3 innings as a left fielder in 2023.  The Red Sox responded to the fielding struggles by limiting Yoshida almost exclusively to DH duty in 2024, a decision that reportedly didn’t please the 31-year-old.

Since the Mariners could use a left-handed bat and basically hitting help of any kind, Yoshida might have some appeal on paper to Seattle.  That said, Randy Arozarena is set to play left field and Mitch Haniger is already slated to take on the bulk of DH at-bats, so Yoshida would again likely be limited to a platoon DH role in the Mariners’ lineup.  It is also easy to imagine what the M’s had little to no interest in taking Yoshida’s contract off Boston’s hands, as reports have indicated that the Mariners might only be open to moving Castillo in order to clear his salary from the books.

Castillo is owed $68.25MM in guaranteed money from 2025-27, plus a $25MM vesting option for 2028 that becomes guaranteed based on health, and if Castillo tosses at least 180 innings during the 2027 season.  Trading Castillo and taking back Yoshida would represent only $39.25MM of savings for the Mariners’ payroll, which the M’s probably didn’t view as worthwhile even with the bigger benefit of obtaining a controllable young slugger like Casas.  Seattle president of baseball operations Jerry Dipoto has publicly stated that trading from the rotation is a “Plan Z” option given how much the Mariners value their elite pitching staff, and if the M’s did budge on moving a starter, taking back an unwanted contract as salary offset is surely not on Dipoto’s radar.

It seems increasingly clear that the Sox are ready to move on from Yoshida, yet naturally it will be tricky in getting another team to absorb anything more than a fraction of his $54MM remaining salary.  Attaching Casas or another young player to Yoshida in a trade package would be a significant sweetener, even it could also be viewed as something of a waste of a trade asset to give up young talent as part of a salary dump.  While $54MM obviously isn’t a drop in the bucket, Yoshida’s contract isn’t all that onerous for a big-market club and a traditional big spender like the Red Sox, plus their estimated $212MM luxury tax number for 2025 is well under the $241MM tax threshold.

That said, the Red Sox have also exceeded the tax line just once in the last five years, as ownership has made a clear mandate to scale back the team’s spending.  This hasn’t stopped Breslow from making some significant moves, though Boston’s pitching acquisitions this winter (i.e. trading for Garrett Crochet and signing Walker Buehler and Patrick Sandoval) came with a pretty limited financial cost.  The Sox have also been linked to such major free agent names as Juan Soto, Max Fried, Corbin Burnes, Teoscar Hernandez, even if those players ultimately ended up signing elsewhere.

The Mariners and Red Sox have been seen as natural trade partners, as Seattle’s pitching depth and need for hitting dovetails with Boston’s rotation needs and surplus of position players.  Considering the quality of the Mariners’ arms, it is safe to guess the Sox would still be open to adding a Seattle starter if an acceptable deal could be lined up, but the two clubs have been unable to find a match after at least a year of on-and-off trade talks.