The Boston Red Sox placed right-hander Brayan Bello on the 15-day injured list Wednesday with right lat tightness.
The team recalled RHP Zack Kelly from Triple-A Worcester in a corresponding move.
Bello is the latest injury for the Red Sox, who have a league-leading 13 players on the IL, including rotation hurlers Lucas Giolito (elbow surgery), Nick Pivetta (elbow strain) and Garrett Whitlock (oblique strain).
Bello is 3-1 with a 3.04 ERA in five starts. He last pitched Friday, earning the win over Pittsburgh. His IL stint is retroactive to Sunday.
Bello is 17-20 with a 4.22 ERA in 46 career appearances (44 starts) in three seasons with the Red Sox.
Kelly is 1-0 with a 3.91 ERA in 21 career relief appearances for Boston but has not appeared in a game yet this season. He has one save and has not allowed a run in six appearances (9 IP) at Worcester.