Sonny Gray's Elite Advanced Metrics Project High-End Starter Role for Red Sox

Sonny Gray, 36, acquired by the Boston Red Sox, shows elite underlying metrics despite a 4.28 ERA in 2025. His 3.29 SIERA ranked 6th in MLB, and his 21.6-point K-BB% difference (26.7% K, 5.0% BB) was 7th highest among qualifiers. Steamer projects 3.9 WAR for Gray in 2026, ranking 9th among pitchers. The Red Sox received $20 million from St. Louis, reducing Gray's guaranteed commitment to $21 million, preserving financial flexibility after trading prospect Brandon Clarke.