Red Sox reliever Zack Kelly undergoes successful elbow surgery, could still return this season

Kelly injured his throwing elbow during his relief appearance against the Rays at Tropicana Field. Because the 28-year-old was visibly emotional as he walked off the mound that night, there was an initial fear that he sustained serious damage to the UCL (ulnar collateral ligament) in the elbow.

Had that been the case, Kelly likely would have required Tommy John surgery. Instead, his MRIs showed no damage in that area, but they did reveal that his ulnar nerve had become detached. As noted by Cotillo, that diagnosis was considered to be “a best-case scenario” at the time.

Kelly underwent an internal bracing procedure on his right elbow in lieu of Tommy John surgery in May 2020, so he has dealt with this sort of issue before. He was with the Angels at that time and would have missed the entirety of the 2020 minor-league season had it not been cancelled due to the COVID-19 pandemic. Kelly was released by Los Angeles shortly thereafter and joined the Red Sox organization as a minor-league free agent that December.

A former undrafted free agent out Division II Newberry College (S.C.), Kelly debuted for Boston at the age of 27 last August. The Virginia native posted a 3.95 ERA and 4.28 FIP with 11 strikeouts to four walks in 13 appearances (13 2/3 innings) to close out the 2022 campaign. He then leveraged that performance and a strong showing in spring training into making his first Opening Day roster this year.

Prior to injuring himself on April 12, Kelly had allowed just one run through his first five outings of the year. He was transferred from the 15-day to the 60-day injured list on April 16 so that the Red Sox could create a 40-man roster spot for left-handed reliever Brennan Bernardino.