Michigan St. doesn't comment on injuries. When Cook got injured, he looked like he was in a lot of pain. Dantonio is going to downplay it, but he had to change his scheme vs. OSU which caused the Buckeyes problems. He also had to ask his defense to step up and that was the difference in the game. OSU prepared for one MSU and didn't expect MSU to run exclusively in 2nd half. OSU wasn't prepared for that.
I know shoulder injuries can take time to heal. From personal experience, I don't think Cook will be good to go until bowl season.