Right-handed pitcher Juan Valera -- Boston’s No. 4 prospect, per MLB Pipeline -- underwent Tommy John surgery on Wednesday, Red Sox senior director of player development Brian Abraham told MLB.com’s Ian Browne.
The surgery was performed by Dr. Jeffrey Dugas in Alabama.
Valera, 19, had quickly become one of the top arms in the Red Sox farm system. The hard-thrower pitched to a 1.93 ERA in three starts this season for High-A Greenville, notching 17 strikeouts in 9 1/3 innings thanks to elite swing-and-miss stuff.
He departed his start on April 16 against Bowling Green after just one inning due to elbow inflammation.
Last season, Valera missed more than three months with a sore elbow. But he appeared to have turned a corner following an up-and-down, injury-plagued 2025 campaign with a strong start to 2026.
Valera originally signed for $45,000 with the Red Sox in 2023 out of the Dominican Republic. He owns a 3.72 ERA in 46 career Minor League appearances (30 starts), with 162 strikeouts in 138 innings.