Red Sox Acquire RHP Sonny Gray From Cardinals

The full deal will send right-handed pitcher Richard Fitts, left-handed pitching prospect Brandon Clarke and a player to be named later or cash to St. Louis in exchange for Gray.

Fitts, the 25-year-old Boston acquired in the Alex Verdugo trade with the Yankees, has a career 3.97 ERA in 65.2 MLB innings. He opened 2025 on the MLB roster, but dealt with injuries and inconsistent performance. Fitts ended the year with a 5.00 ERA and a 5.80 FIP across 11 appearances.

The 2025 season aside, let’s break down this trade for both parties.

The Red Sox Side

As it stands, here’s the projected Opening Day rotation for Boston:

Still seems like there’s work to do at face value, but it’s certainly a more formidable rotation than what they finished 2025 with. Compared to what the Red Sox got out of Lucas Giolito, they should be happy with what Gray brings to the table.

Now, what exactly is that?

The right-hander feels more like a 2024 Red Sox starter in the sense that his fastball got crushed this past season, so there’s a strong chance his usage of it is cut further. He only threw his four-seamer 22.3% of the time, but opponents hit .370 against it with a .585 slug.

Meanwhile, his breaking pitches are among the game’s best. His sweeper specifically is dominant, holding opposing hitters to a .150 average and a 42.3% whiff rate.

Gray also hammers the strike zone, ranking in the 93rd percentile for walk rate, but he can also get hitters to chase when he needs to.

As a team, the Red Sox posted just a 27.1% called-strike-plus-whiff rate (CSW%) in 2025, that tied them for 18th in baseball. Gray posted a 30.8 CSW%, which bests that of ace southpaw Garrett Crochet.

Moreover, the Red Sox acquired a legitimate front-of-the-rotation starter without trading an outfielder. As a result, they can either continue upgrading the rotation via trade or target an infielder with Jarren Duran or Wilyer Abreu as the outgoing headliner.

Gray’s expected production aside, the options this trade gives Boston make the deal a home run at the outset.

The Cardinals Side

Even though they’re sending $20 million to the Red Sox to complete this deal, the Cardinals should be happy with how they make out here.

Fitts fell out of favor in Boston, mostly due to circumstance. He won the No. 5 starter job in Spring Training and pitched well enough early in the season for the team to trade his competition, Quinn Priester, to Milwaukee.

Unfortunately, he strained his pectoral muscle in an April start and never regained the momentum earned in camp. He had a 3.18 ERA to that point, but a 6.11 after missing six weeks.

There were really nice flashes from the right-hander, though. He saw dramatic increases in velocity in Spring Training, and he posted a 32.8% chase rate in 2025. If those whiff numbers catch up, the Cardinals have a weapon on their hands for several seasons.

Regardless, he’s at worst quality depth for the rotation with the ability to pitch in relief if need be.

As for Clarke, there’s uncertainty about his ceiling as a big-league contributor. Not that he can’t be a big leaguer, but there are some early warning signs he’s a long-term reliever.

That said, he’s got an electric fastball with really nice shape on his breaking pitches. If he can button up his command — 15.5% walk rate in 2025 — he has the stuff to fly through the minor leagues.

The Red Sox selected him in the fifth round in 2024, and he opened the season as the organization’s No 10. prospect. There’s a lot to like about this southpaw, so it’s no wonder the Cardinals wanted him.