Chris Carpenter's career may well be over after a setback from nerve injuries that cost him most of last season. Carpenter tortured Pirates hitters for nearly a decade, holding them to a .598 OPS against over his career.
Carpenter wasn't a bad pitcher in his first several years with the league, but the grand leap forward he took after joining the Cardinals demonstrates how unpredictable pitchers' careers can be. Among his peers, the pitcher who had the most similar career path is probably former Pirate Jason Schmidt, who, like Carpenter, left the team he'd spent most of his early career with and blossomed into one of the better pitchers in the league in his late 20s. Carpenter's peak lasted longer, of course, and through a series of injuries.
Anyway, the Cardinals might well just plug Shelby Miller into Carpenter's spot and do just fine, and of course the Cardinals are still the only team that doesn't have to pony up a draft pick for Kyle Lohse, but this is still a tough day for Cards fans.