Having seen Amir's play in the best game i saw live, and how instrumental he was in the big win over OKC, i couldn't possibly give him less than a B. He was huge in keeping this team's focus on winning when it wasn't supposed to be. The stats mean very little. He's the perfect example of a player whose value is not relative to stats. Ask his teammates what his grade should be. I think they would probably all grade him pretty high. There is a reason this team feels they can compete with anyone, and he is a large part of that, and they know it.
That said, i am worried about the damn ankles. It would seem as though they are basically sausages at this point. And that sucks just to think about. A lot of the defensive effectiveness of this team rests on him, and that is not overstating anything.