Yeah, you kind of have to get a little lucky with the type of injury and the timing. Say it's late in the season and a player gets a season-ender but he'll be healthy again after rollover... you're out of luck there. Last season my SP1 pitched one game and blew his elbow out, at the age of 36. Had never been inured before. He got the one injury recovery bump at the end of the season and that was it, because he was healthy after rollover. I had to let him walk in free agency, he went from SP1 to LR just like that.
And as was said, it doesn't matter much if a pitcher gets a leg injury. Optimum case is he gets like a sprained shoulder at the end of training camp, you can leave him in the training room and he'll still be back after the all star game. And then really optimum case - for training bug - is you get a player who gets like four or five of those types of DL stints.