Red Sox roster moves: Hard-thrower (0.92 ERA) called up for first MLB stint since ‘19; Zack Kelly sent down
The Red Sox will add a hard thrower to their bullpen before beginning a homestand at Fenway Park on Friday. Boston has selected the contract of 35-year-old reliever Tayron Guerrero from Triple-A Worcester and Guerrero will be active for Friday’s series opener against Minnesota, a source confirmed. To make room for him on the active roster, the Red Sox have optioned righty Zack Kelly to Triple-A Worcester, where he started the year before being called up a week into the regular season, according to sources.
Righty Kutter Crawford, who has not pitched yet this season, was transferred to the 60-day injured list to clear a 40-man roster spot for Guerrero. That is a paper move that doesn’t impact Crawford’s timetable for a potential return. Guerrero, who signed with Boston as a minor league free agent in January, earned a return to the majors with a stellar showing in Worcester, where he logged an 0.
92 ERA (2 earned runs in 19 ⅔ innings) while allowing 13 hits and working a 22-6 strikeout-to-walk ratio in 15 games. Guerrero has consistently hit triple digits with his fastball in Triple-A after impressing during spring training . “I saw him attacking,” Red Sox catcher Mikey Gasper said about his time catching Guerrero in Worcester before being called up to Boston.
“He’s throwing a heavy fastball at 99 and he’s attacking the zone with it. ” Guerrero is a Colombia native who stands 6-foot-8 and weighs 225 pounds. He last pitched in the majors in 2019, when he logged a 6.
26 ERA in 46 innings for the Marlins. He appeared in 113 games for the Padres and Marlins between 2016 and 2019 before bouncing around the minors and various international leagues. He spent 2025 with the Chiba Lotte Marines in Japan.