Gasper will undergo surgery Friday to repair a torn right biceps, Rob Bradford of WEEI.com reports.
Gasper's biceps tendon tore completely off the bone on a swinging strikeout during a Sept. 25 contest against the Cubs. He will be unavailable for the entirety of the postseason, and it's unclear how long the rehab process will take. Assuming health, Gasper should be in the mix for a utility role with the Red Sox again next season after slashing .251/.357/.466 with 10 home runs and a 27:39 BB:K over 67 games in 2026.