Based on watching the video here are my guesses 1) Subluxation. That's when it pops partially out and right back in, but it leaves it feeling dead for a while. Based in his reaction, that's what it looked like to me. Then again, a subluxation is very minor, Benson is a professional football player, so he should be able to deal with pain, that's what leads me to thinking it's a bit more serious. 2) Separation. Depends on severity, hopefully it wouldn't keep him out too long.