The Boston Red Sox acquired pitcher Sonny Gray from the St. Louis Cardinals on Nov. 25 to bolster their rotation behind ace Garrett Crochet. While Gray's 4.28 ERA in 2025 raises questions about his value at age 36, advanced metrics like SIERA suggest he remains a high-end starter. The deal provides Boston with cost-effective pitching depth and future flexibility.
The Red Sox aimed to secure a No. 2 starter this offseason, pairing it with ace Garrett Crochet. On Nov. 25, Boston completed a trade with the St. Louis Cardinals for Sonny Gray, a three-time All-Star. Skeptics point to Gray's 2025 performance, where his 4.28 ERA ranked 50th among the 70 pitchers who threw at least 150 innings.
However, deeper analysis reveals strengths beyond the surface. Gray's strikeout rate stood at 26.7%, with a walk rate of 5.0%, creating a 21.6-point difference—the seventh highest among qualifiers. His SIERA of 3.29 ranked sixth in MLB, a full run below his ERA, indicating potential bad luck or defensive support issues.
Gray joined elite company in the lowest SIERA rankings for 2025 (minimum 150 innings):
- 1. Tarik Skubal: 2.71 (AL Cy Young winner)
- 2. Garrett Crochet: 2.86 (2nd in AL)
- 3. Cristopher Sánchez: 3.02 (2nd in NL)
- 4. Paul Skenes: 3.10 (NL Cy Young winner)
- 5. Logan Webb: 3.14 (4th in NL)
- 6. Sonny Gray: 3.29
- 7. Bryan Woo: 3.30 (5th in AL)
- 8-T. Yoshinobu Yamamoto: 3.32 (3rd in NL)
- 8-T. Jacob deGrom: 3.32 (8th in AL)
- 8-T. Joe Ryan: 3.32
- 11. Hunter Brown: 3.39 (3rd in AL)
Only one other top-11 SIERA pitcher besides Gray missed Cy Young votes. Projections for 2026 are promising: Steamer forecasts Gray at 3.9 WAR (ninth among pitchers), with Crochet at 5.6 WAR (third), making Boston the only team with two in the top 15.
The trade's structure benefits Boston financially. The Red Sox parted with two pitchers, including prospect Brandon Clarke, but received $20 million from St. Louis to offset Gray's 2026 salary and the buyout of his $30 million 2027 club option. This commits Boston to just $21 million for Gray, allowing room to pursue a middle-of-the-order bat. For comparison, free agent Dylan Cease signed a seven-year, $210 million deal with the Blue Jays.