Blake Treinen, a setup man who is one of the Los Angeles Dodgers' most important relief pitchers, was placed on the injured list Friday with what the team described as right shoulder discomfort.
The severity of Treinen's injury was not yet known.
Treinen, who had a 2.48 ERA in 99 appearances for the Dodgers over the past two years, won't be eligible to return off his 10-day IL stint until next Friday at the earliest. Treinen last pitched April 14, but teams are not allowed to back-date IL stints by more than three days from the time when they make the roster move.
The Dodgers initially hoped that a few days off would allow the 33-year-old right-hander to become available for this weekend's series against the San Diego Padres.
In Treinen's absence, the likes of Daniel Hudson, Brusdar Graterol and Alex Vesia will be relied on more heavily to bridge the gap for new closer Craig Kimbrel.
The Dodgers (9-3), who lead the majors with a .750 winning percentage entering Friday's games, called up left-hander Garrett Cleavinger to take Treinen's spot on the active roster.