Quinn has 2 "alterts" one his his injuries, the other is the position move. We know he can handle the going forward part of a 3-4 OLber/40 nickel end. He can rush the passer, he can handle a gap in run game. How can he handle dropping to the flat? or the hook? or even man coverage on a back.
Phillips will try to avoid having him in coverage, but there will he times he has to do it if they are in their base defense. You cannot have Barwin drop all the time and rush Quinn.
So, that is the question and I submit no one knows if he can do that well enough...even if it is just 3-4 snaps a game. When we see him in preseason we will know.
The health is also an unknown. He's going to be 27, should still have 2-3 years in prime, but injuries can just be bad luck or it could be that he's injury prone. Either way, those "alerts" will be seen and he can answer them. If not, he needs to be cut or traded. If he can handle is responsibilities and get 12-16 sacks, he's a star again.
