If teams discovered for sure that he's got a bare spot (bone on bone) in either of those knees, it's a pretty huge concern. Not even a "cross your fingers" concern like an ACL tear would be. It's a "how long do you think he has" concern.
Most I've heard strictly consider him a 4-3 end. With that said, and the knee problems, very doubtful Texans take him. With his talent it would be interesting though.
Its questionable if he can play the 3-4 end so he's probably not going to be able to play 3-4 linebacker. He reminds me of Mario, a legit 4-3 DE. Schefter is reporting his knee is messed up still (bone on bone) and needs to have another surgery probably within the next 3 years that will sideline him for about 8 months.
Hello, microfracture! (Can it be fixed with that?) The Texans would never take him, the coaching staff and GM care too much about their own asses to put the team ahead of themselves. Also I have a feeling that the Cowboys will take him, it seems like a Jerry Jones pick.