Tigers pitcher Bruce Rondon has tendinitis in right shoulder
Rondon, 24, missed the entire 2014 season after having Tommy John surgery on his right elbow.
He will begin the season on the disabled list.
Rondon was cleared to pitch in March and has appeared in eight spring training games, pitching 7.1 innings and allowing an opposing batting average of .313 with a 4.91 ERA.
Rondon pitched on Tuesday and was scheduled to pitch the next day but woke up with a sore shoulder.
"If he can't pitch, obviously it's a lot tougher to be on the team. In that sense, it's a big concern,” Tigers manager Brad Ausmus said to MLB.com. “He needs to pitch back-to-back before we can assume that he's OK to pitch on a regular basis at the Major League level."
In his first full season in the majors in 2013, Rondon went 1-2 with one save and five holds in 30 appearances primarily as a set-up man.
- Scooby Axson