I agree he's not built like a traditional Guard, but it's not 1978 any more either. If it does turn out he doesn't have the feet to play Tackle at this level, you're not going to cut him or just stick him on the bench. He's the kind of guy you want on the field.
As for him getting murdered inside; I'm not buying that. He doesn't strike me as somebody you want to fight in a phone booth.