As an aside, I think we're going to see a lot of Graham getting rested at least a day a week.
First, he doesn't need to know the offense. He's got it down, and he's obviously got it down with Russell. Yea, I'm sure both guys would agree they could always get better.
They're probably worried about that knee still. The less contact the better.
The biggest one (in my mind) is how he plays the game. Watch the next game. You NEVER see anyone take Jimmy up high. he's such a big dude, and he'll give you a mean stiff arm from 4 ft away with those arms, that guys are always going low. If you watch Graham after the catch, the guy takes a LOT of shots to the legs. I think a lot of the rest he gets is to rest up his legs. They really take a beating.