Well, I've gotta think he prolly did do juice. Why? Because he is so huge and buff? No. How about because he is an actor, and probably does not want the kind of pain, nor has the discipline necessary to get there without drugs.
Think about it. He only has x number of weeks to get ready. Hmmmm, he could stop partying, or he could juice it up, get ripped, do the movie, and move on.
Hell, why not. He has got better things to do than say no, I don't think I will go out and party, because I want to get my six pack.