Could Josh Naylor trade get Red Sox what they want from Mariners for Triston Casas?

As of right now, the Boston Red Sox don't need a first baseman. Triston Casas is set to return fully healthy to the position in the 2025 season and get back to living up to his 40-homer potential. However, the current state of the first base market in free agency this winter could be of quite a bit of interest to Craig Breslow with how things are playing out.

Throughout the offseason, there have been rumblings about the possibility of the Red Sox trading Casas, flipping Rafael Devers from third-to-first, and using their current young first baseman as a prized trade chip to land another pitching upgrade to pair with Garrett Crochet. The problem with those reported discussions to this point, however, has been other clubs completely undervaluing Casas.

The most common link to a Casas trade has been Boston dealing with the Seattle Mariners for veteran right-handed pitcher Luis Castillo. Make no mistake, a 1-2 punch of Crochet and Castillo would be a massive upgrade for Boston — just not at the price of trading Casas. That's a fleece job by Seattle if it were to happen.

Which brings us back to the developing first-base market this winter.

Seattle has been heavily connected to not just Casas but a plethora of other first basemen this offseason given the club's dire need for an offensive upgrade. In the past 48 hours, though, some of their most likely options at the position for the Mariners have come off the board. Christian Walker, Paul Goldschmidt and Carlos Santana have all signed while Josh Naylor was traded to Arizona.

Pete Alonso is now by far the best available option but is also likely out of Seattle's price range. That could lead the Mariners to refocus on Casas and the Red Sox — but Boston would now have the leverage to potentially get the deal they want.

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Red Sox could leverage Triston Casas against Mariners for elite pitcher

It's getting at least close to the point of desperation for the Mariners in their search for more offensive firepower. That could work to the Red Sox' benefit if Craig Breslow is willing and able to capitalize on it.

For as good as Castillo would be as a No. 2, Casas should always have been in talks for a higher return. In fact, one report indicated that Breslow recognized this, looking at either Bryan Woo or Bryce Miller — but Seattle turned that down. Perhaps that's something that could be revisited and, with how the market is shaking out, be of more interest to the Mariners.

Or, if you really want to think about pie-in-the-sky, the Red Sox could really take a massive swing and offer some package centered around Casas and young outfielder Wilyer Abreu to get either Seattle ace, Logan Gilbert or George Kirby, in return. Boston has the outfield depth with the looming debut of top prospect Roman Anthony to pull a deal like that off if the Mariners were so inclined.

None of this is a formality, of course. There's a chance that the Mariners aren't desperate at all and, instead, are content to settle on a lesser option at first base. However, if there is even an inkling that Breslow sniffs out that Boston has far more leverage than they did before, he should jump on the phone and look to make a trade that would substantially shift the tides of the Red Sox offseason toward the better.