He actually had two major injuries this season. The first was Tommy John, which he had in the offseason and, apparently, he was slow to recover from it. There were some questions about how much it affected his performance last season, although it's unclear about how much it affected him and what parts of his game were affected. The second injury was a head-on collision back around April/May, where he and Daytona OF Tony Campana collided in the outfield. Both had to go to the hospital, with Colvin taking the worst of the impact. I believe he sustained a rather serious concussion from that collision. So, my gut is that it took him some time to fully recover from both injuries.