More than the drugs, his low weight and the resulting pounding he'll take from NFL OTs are more concerning.
He broke his leg earlier in his career and then this past year had knee, head, and ankle injuries. Those injuries kept him out of the game against Iowa where I would have been really interesting to see him go against Scherff.
325 lb OTs going against 225 LBs can have a negative effect on the human body...
He has to gain weight.
He has already gained weight since the combine. He is almost 250 now, before even getting in an NFL strength and nutrition program. Like most great pass rushers, he's so long that he looks a little thin, like Aldon Smith did.
He will play in the 260'ish range and be more than fine. He is going to be in a rotation with Hardy, Lawrence, and Mincey anyway early on in his career. He will get in on nickle plays and will be able to pin his ears back and go after the QB.
I understand why you don't like to see Dallas get him and don't like the idea of him and Hardy getting after Aaron Rogers... but no need to make things up like he's too light to play.