I was not aware of his history of injuries. I guess the Dodgers may have been concerned about his ability to remain injury free when they let him go. Regardless of why he left he was a large part of the Dodgers getting to the World Series last year and they (dodgers) did little, if any, effort to replace him.
I actually feel bad for Roberts. I think he is a good manager who is deserving of a new contract-one that management has avoided so far this year. He may just take the ax if the Dodgers don't make the playoffs. The reason is management needs to "do something" so that fans will continue buy those huge hot dogs. Since management can't fire themselves, and can't fire players, that leaves the manager.