Judging by his twitter feed he said he was going to have a MRI on Jan 6th, but hasn't commented on his injury since. You'd think if it was something like an ACL, he would have had surgery by now.
You would never wait 6 weeks to have surgery on a torn ACL. Swelling goes down on a week, or less with therapy. Pre-surgery therapy is also deemed mostly unnecessary especially for someone in good shape.
My roommate in college waited a little over a month to have surgery for swelling and stuff to go down and he had pre-hab of his knee. His knee was certainly swollen a month out. I googled it to make sure I wasn't going crazy and that seems like fairly standard operating procedure, but I don't know.