The Mariners’ pitching depth over the last few seasons has drawn many teams into trade talks and it was almost exactly a year ago that reports surfaced about Boston’s interest in the Seattle rotation.  Nothing materialized between the two teams then, but Ryan Divish and Adam Jude of the Seattle Times report that earlier this offseason, the Red Sox offered first baseman Triston Casas for either Bryce Miller or Bryan Woo.  However, these “exploratory talks” then “didn’t progress any further,” as the M’s don’t have interest in trading from their rotation unless it is something of a last resort.

Given the contrasting strengths and weaknesses of the Mariners and Red Sox, a pitching-for-hitting swap would seem like an ideal answer to both team’s needs.  While Miller or Woo might not be precisely the kind of ace the Sox are looking for to reinforce their rotation, obviously both are talented young arms with upside and team control — neither Miller or Woo is eligible for arbitration yet, and both are controlled through the 2029 season.  Likewise, Casas is controlled through 2028 and has already shown glimpses of his potential at the MLB level.

Seattle president of baseball operations Jerry Dipoto has consistently turned down past offers for Miller, Woo, George Kirby, Logan Gilbert, and Luis Castillo.  Recent reports suggest that the M’s are at least open to hearing what teams have to say about Castillo (the oldest and highest-paid member of the rotation), but Divish and Jude write that “the Mariners….are not actively shopping Castillo.”

Nothing is stopping Dipoto from hearing what teams might have to say, just in case someone steps forth with an offer too good to refuse.  However, Dipoto told Divish and other reporters today that “our initial reluctance to any type of deeper discussions on trading starting pitching has probably resulted in a lot fewer phone calls than we’ve usually fielded to this point in the offseason.”

The result is perhaps something of a stalemate, as the Mariners are waiting for rival teams to lower their asking prices and other clubs are waiting for the M’s to become more open to the idea of trading from the rotation depth.  Things could evolve once some free agent pitchers come off the board, or perhaps if the Mariners themselves added a pitcher in the form of Roki Sasaki.  While virtually every team in baseball will be making an appeal to the Japanese ace now that his posting window is officially open, Seattle’s track record with both pitching development and star Japanese players would seemingly put the M’s move above most teams in the bidding process.

In the interim, it seems as though the Mariners will continue to focus on trying to trade from its minor league depth, except as Dipoto notes, “it’s the time where prospects aren’t a driver, where just about everybody is focused on major league players.  And I don’t know why that seems different to me now than it usually does, and maybe that too changes in a week or two with the free agent market really opening up.”

Since shortstop J.P. Crawford is the only established member of the Mariners’ infield, landing a promising first base talent like Casas would go a long way towards shoring up the infield and the shaky lineup as a whole.  That said, the Mariners have at least a part-time first base option already in Luke Raley, who looks to be getting a good chunk of playing time against right-handed pitching.

Since the M’s have been linked to such second or third base trade candidates as Nico Hoerner or Alec Bohm, it could be that Seattle might be trying to address one of those positions first before turning to the comparatively easier-to-fill position of first base.  An industry source told Divish and Jude that the Mariners could look into trying to add a third team into talks with the Cubs about Hoerner, perhaps to help cover some of the money owed in the remaining two years of Hoerner’s contract.

From Boston’s perspective, trading Casas wouldn’t necessarily create a vacancy at first base.  Rafael Devers is a subpar defender at third base, and reportedly the Sox have at least considered moving him to first base in order to open up the hot corner either for one of Boston’s up-and-coming infield prospects, or perhaps for a big free agent like Alex Bregman.  This remains a speculative topic for now, as manager Alex Cora told reporters (including Pete Abraham of the Boston Globe) today that he hasn’t spoken with Devers about a position change, and Cora in fact praised Devers’ third base work in 2024 as “outstanding.”

Then again, there is no shortage of gamesmanship going on during the offseason, as it was just last month that Red Sox chief baseball officer Craig Breslow downplayed the idea of trading Casas.  Reports then surfaced this past weekend that the Sox were considering the possibility of dealing Casas for pitching, and this apparent offer for Miller or Woo only reinforces the idea that Casas is far from an untouchable part of the Red Sox roster.  Of course, this also isn’t to say that Casas is going to be moved for anything less than a premium return.