What the Sonny Gray Trade Means for the D-backs’ Search for Starting Pitching

The Red Sox–Cardinals deal for Sonny Gray sets a clear benchmark for the 2026 starting-pitching market. Here’s how it reshapes the D-backs' options and potential cost for rental starters.

The first major domino in the starting pitching trade market has fallen. Jon Heyman of the New York Post reports that Sonny Gray is heading to the Boston Red Sox. Per ESPN’s Jeff Passan, going back to the St. Louis Cardinals are right-hander Richard Fitts and left-hander Brandon Clarke. The Cardinals are also sending $20 million in cash to the Red Sox.

Gray is still a top-of-the-rotation arm, save for a 4.28 ERA in 2025. Advanced metrics paint the picture of a stronger performance, with a 3.90 xERA, 3.39 FIP, and 3.07 xFIP. His Statcast page shows he’s excellent at inducing chases (31.2%) and whiffs (27.5%). Those show up in his 26.7% strikeout rate and 5.0% walk rate, with his 21.6 K-BB% ranking 7th among qualified MLB starters.

There are some quality of contact concerns, as he yielded a 41.1% hard-hit rate and a 9.8% barrel rate. This paints the picture of a starter who has excellent command, but will watch in-zone mistakes get hammered. Overall, I’d consider it a good gamble for the Red Sox, and the Cardinals got a quality return for him.

This deal provides clarity for the Arizona Diamondbacks and what it might cost to improve their rotation. The rebuilding Cardinals picked up an MLB-ready arm (Fitts) and a volatile arm with upside (Clarke) for Gray’s final guaranteed year under contract. The D-backs aren’t going to be trading MLB-ready starter prospects, due to weak organizational depth.

Arizona’s likely equivalent to that package is likely infielder Jordan Lawlar and right-hander David Hagaman. Lawlar is an MLB-ready shortstop who’s been pushed off his natural position with Geraldo Perdomo’s extension and breakout in 2025. Hagaman is an upside play for the rotation, as he could very well be their top pitching prospect a year from now. However, I don’t see it as likely that the D-backs will ever consider moving Hagaman for a rental starter.