Tigers reliever Joel Zumaya has been missing since spring training after developing discomfort in his surgically-repaired throwing elbow. Exams showed no structural damage and Zumaya was cleared to begin a throwing program in early April, but that throwing program was delayed when Zumaya began experiencing renewed discomfort in the form of radiating pain.
Zumaya went to see Dr. James Andrews, and Andrews didn't find any nerve damage in Zumaya's elbow. Still, that left Zumaya with a choice: attempt to rehab the elbow, or undergo exploratory surgery. According to Jason Beck, Zumaya has opted for rehab.
Surgery would have knocked Zumaya out for pretty much the entire season, so he's trying to avoid that outcome if possible. So he's going to enter a six-week rehab program instead before he can resume throwing. If all goes well, he return to the Tigers somewhere in the vicinity of the All-Star Break, but this being Joel Zumaya, we probably shouldn't assume that everything will go well.