The Diamondbacks reassigned Medlen to their minor-league camp Monday, Steve Gilbert of MLB.com reports.
Medlen has worked as a starter for most of his big-league career, but with no rotation spots up for grabs in Arizona, the right-hander had been competing for a long-relief role in spring training. The 32-year-old didn't provide many signs during the exhibition schedule that he would be a useful bullpen arm, finishing the spring with 11 runs allowed (nine earned) on 18 hits and seven walks over 15.1 innings. Medlen will presumably report to Triple-A Reno and return to a rotation role, but it's difficult to imagine him resurfacing in the big leagues this season as anything more than a short-term starter.