The Boston Red Sox have been relatively inactive at the trade deadline compared to other contending teams. The latest rumor from Francys Romero suggests that may change soon.
Romero reports that the Red Sox have been in contact with the Arizona Diamondbacks about pitcher Merrill Kelly. Kelly is on an expiring contract and would be a true rental, which chief baseball officer Craig Breslow initially hoped to avoid. Teams selling controllable starters have requested astronomical returns, so Kelly may be the best option for Boston in the tight American League, despite Breslow's previous desires.
Kelly is possibly the best rental pitcher available on the market this year. The veteran has posted a 3.22 ERA and a 1.06 WHIP with 121 strikeouts and 38 walks over 128.2 innings this season. He's been even better in recent weeks, with a 2.81 ERA in his last seven outings.
The Diamondbacks also have Zac Gallen on the market as a rental pitcher, but he hasn't had nearly as good a season as Kelly. The 29-year-old has had the worst season of his career so far, with a 5.60 ERA, 121 strikeouts and 47 walks in 127 innings pitched.
Red Sox are in talks with Diamondbacks about veteran rental pitcher Merrill Kelly
The Arizona Dbacks are in talks with the Boston Red Sox about right-hander Merrill Kelly, sources tell me.
— Francys Romero (@francysromeroFR) July 31, 2025
Chris Cotillo of MassLive made an interesting prediction about the Diamondbacks' asking prices for Kelly and Gallen. Both are impending free agents and qualifying offer candidates. If Arizona were to issue them qualifying offers and they decline, it would be given compensation round draft picks for the loss of the pitchers. Cotillo suggests the returns for Kelly and Gallen on the trade market would need to have comparable value to the compensation picks the Diamondbacks would lose out on by trading them.
Even after Kristian Campbell, Marcelo Mayer and Roman Anthony graduated from prospect status, the Red Sox's farm system is deep. Breslow has drafted well in his first two seasons at the helm of the organization, and Boston has plenty of prospects it could send Arizona's way for Kelly. Whether Breslow will be willing to part with them is another question entirely.