The Boston Red Sox will be buyers at this year's MLB trade deadline, and they have several needs Craig Breslow should look to address. Their rotation could use a No. 2 starter to plug behind Garrett Crochet. Their bullpen could use a high-leverage arm to help set things up for Aroldis Chapman. Their lineup could use another big bat, particularly at first base. That's where Yandy Diaz comes in.
Diaz would be a dream pickup for a couple of reasons. First and foremost, he's one of the best and most underrated first basemen in the game. Second, he's controllable, as he has a $10 million club option for the 2026 campaign. Adding an All-Star-caliber player at a position of current need sounds like a no-brainer for a contender, but doing so could put fan favorite Triston Casas on thin ice in Boston.
More smoke on the Yandy Diaz front from @ChrisCotillo:
— Tyler Milliken (@tylermilliken_) July 27, 2025
“Especially intriguing to the Red Sox, according to a baseball source, is that Díaz is under control beyond 2025. Privately, the club is not guaranteeing that Triston Casas… is guaranteed to be the starter in 2026.” pic.twitter.com/JKQdOBTBYs
Mass Live's Chris Cotillo reports that Diaz is particularly intriguing to Boston because of his additional year of club control he'd come with. He also noted that Casas is not guaranteed to be Boston's starter in 2026. That'd be... something.
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Triston Casas isn't building block Red Sox thought he was
Ahead of the 2025 campaign, Casas was looked at as a key piece not only for 2025, but beyond as well. He hit clean-up on Opening Day, and figured to have a good chance of hitting in that spot for the next decade if he lived up to his potential. Unfortunately, he had a .580 OPS in 29 games, leading the team to bump him down in the order. Then, Casas' season ended prematurely after those 29 games after he ruptured his patellar tendon running to first base. Casas has had some good moments, but has struggled to stay on the field in his brief career, and has been inconsistent when he's been able to suit up.
Diaz, on the other hand, has been mostly durable and nothing but consistent for the better part of the past half-decade. Acquiring Diaz to help them now and in 2026, only to then flip Casas, could make sense.
It might not be ideal to trade Casas coming off what's essentially a lost season, but what would the alternative solution be? Benching Casas should not be considered, and he's only a first baseman. Sure, Boston could choose to DH either Casas or Diaz, but part of why Boston traded Rafael Devers was so that they would have more flexibility at the DH spot. Plus, with Masataka Yoshida still under contract, it'd be extra foolish. This means if the Red Sox choose to acquire Diaz, and it should be seen as a big if, they should trade Casas.
Triston Casas can help land Red Sox dream No. 2 starter
While Casas certainly has his faults, there's no disputing he's got a good amount of value. He's a 25-year-old who was a highly touted prospect and has an .800 OPS in parts of four seasons. In 2023, the only season in which he's played more than 63 big league games, Casas launched 24 home runs and had a 129 OPS+. He also comes with three additional years of club control.
The Red Sox would need to add more, but Casas plus some high-end prospect capital can help land Boston its dream No. 2 starter to pitch behind Garrett Crochet that it's needed. This kind of deal won't happen until the offseason when Casas is healthy, but if the Red Sox choose to trade for Diaz instead of a rental like Ryan O'Hearn, there's a good chance Casas will have played his last game with Boston.