CM Punk actually has 4 different injuries to his knee at one time. Punk has a lot of pain in his lower leg but not the knee itself, despite the number of injuries. He has a strained ACL and other torn ligaments.
Before the leg injury, Punk was already planning on taking time off after WrestleMania 29 because he was mentally burnt out. Doctors advised him to stay out of the ring at least 6 weeks. He will not be at this Monday’s RAW from England and how soon WWE asks him to return will likely depend on how the ratings are over the next few weeks.