Getty The St. Louis Cardinals have gotten some big contributions out of their rookie phenom, and they're already thinking of extending him. The St. Louis Cardinals have gotten off to a much better start this season than they were expected to. Through their first five games, they are 3-2 and sit just one game back in the National League Central. They started their season with a dramatic comeback win over the Tampa Bay Rays , rallying from a 7-1 deficit. Their top prospect, JJ Wetherholt made the