The potential trade scenario involving the Boston Red Sox and Seattle Mariners could be taking a new direction, as recent discussions suggest that a deal between the two teams may have a fresh outlook.
For months, various reports have linked the Red Sox to Mariners pitcher Luis Castillo, with many speculating a trade centered around him and Boston’s first baseman, Triston Casas. However, these discussions have never fully aligned with the needs and goals of both teams, raising questions about whether such a move would make sense for either side.
One of the key factors is that the Mariners don’t necessarily need a new first baseman, as they already have Luke Raley, who can play the position. Still, first base remains an attractive spot to add a powerful bat, and with many potential sluggers already off the market, Seattle may be feeling pressure to find a suitable option. If the Mariners miss out on big-name players like Pete Alonso or Alex Bregman—neither of whom have been closely linked to Seattle—they might find Triston Casas to be a worthwhile target to boost their offense.
As the pool of available first basemen dwindles, Cody Williams of FanSided has suggested that the Red Sox could leverage this situation to demand more than just Castillo in any trade talks with the Mariners. Williams pointed to pitchers Bryce Miller and Bryan Woo as potential targets, emphasizing that the Mariners may soon be in a position of needing offensive reinforcements. This could work in Boston’s favor, particularly if Red Sox president of baseball operations Craig Breslow is able to capitalize on Seattle’s growing sense of urgency.
While Luis Castillo would be a valuable addition to Boston’s rotation, particularly as a solid No. 2 starter, some reports suggest that Casas has always been a potential centerpiece in any trade for a higher-value return. In fact, Breslow is believed to have previously expressed interest in either Miller or Woo in exchange for Casas, although Seattle reportedly rejected those proposals. With the market continuing to evolve, this trade could be revisited, with both Miller and Woo potentially becoming more attractive to the Mariners.
Miller and Woo both posted excellent ERAs under three last season, while Castillo’s ERA sat at 3.64. What’s more, both Miller and Woo are under team control for at least four more years, with Woo having five years of control remaining. Though neither pitcher has the same established track record as Castillo, both have the potential to develop into future No. 1 starters.
From a timing perspective, a trade involving either Miller or Woo for Casas would make sense for both teams. Neither the Red Sox nor the Mariners are in an all-in “win-now” mode, but both teams are positioning themselves for sustained success over the long term. Both clubs boast impressive young talent, although it’s concentrated in specific areas of their rosters. A deal like this could fill an immediate need while also benefiting both teams over the course of several years.
The biggest challenge for the Red Sox lies in the positional value of Casas. In today’s market, controllable starting pitching is incredibly valuable, as the Red Sox experienced when they traded away multiple top prospects for Garrett Crochet. Meanwhile, Casas, as a first baseman, must be an elite hitter to offer substantial value at his position. First base is traditionally a power position, so Casas would need to deliver offensively to justify his trade value.
At this early stage of the offseason, anything is possible. If the Mariners continue to miss out on top offensive targets, the Red Sox could find themselves in a stronger position to make a deal that benefits both sides. A potential trade could reshape the landscape for both teams as they look ahead to the 2024 season.
