I'd agree that he can't work like he used to, tonight was concise proof of that with him spending 2/3 of the match on the ground or in restholds. the thing is he's wrestling at 250lbs+ and in worse cardio shape than he was in his prime, thats a lot of weight to be carrying around even if its all muscle from PED usage. not to mention 10+ years older which takes a toll as well.
I could be wrong because in not a pro wrestler, but it seemed to me that the booking of this match was a lot of the problem. For whatever reason Rock never got offense in and he was booked as being on his back the whole match. There were moments when Rock was getting offense in where the match was pretty good.