CM Punk's injuries are adding up. At the SmackDown tapings, Punk was sick and banged up for his match with Dean Ambrose. There have been previous concerns about his health. He tweeted yesterday that his ribs are "busted". No details about that particular injury have been revealed outside of that tweet.
It's also believed that Punk suffered some sort of back injury on RAW last month. There is also concern he suffered a concussion.
There has been a lot of talk of Punk retiring in the next few years. Punk has said he doesn't want to hang around longer than he should and only has two or three years left.