In the 4-3 defense Sullivan has looked good. In the base 3-4 he's been pushed back halfway to New York. He plays the NT spot like he's on roller skates.
He's got to learn to drop the butt and sink though huge hips. He's a lot like Vince was as a rookie.
On the plus side, he uses his hands better than he did just two games ago.
My thinking is that the bottom line on this guy is not his lack of ability, because he has raw talent, but his "tude" that determines if he makes the team.
If he's humping it like there is no tomorrow and keeping his nose clean 24 X 7, BB will keep him.