Does anyone else on MW think Andy has privately had conversations with his team about Novak possibly being on PEDs? Also, I recall that Andy actually said in an interview a while back that some players on the tour don't seem to get tired in long matches. I don't think it takes a genius to think he was probably considers Novak as being one of those players. He obviously can't (and shouldn't) say that publicly but it wouldn't surprise me at all if Andy thinks it in private.
To me it would be surprising if he had not vocalised the possibility of at least one or two major rivals taking PEDS. Whether he'd say this to his team or others i don't know.
Even if he on balance thought they were clean, he is surely going to entertain the possibility. PED use is a widespread reality in many sports - how affected tennis is we don't know, but we have already had a recent mens slam winner done under doping rules (Cillic).
Andy has certainly taken a close interest in the Armstrong case. It must be a dark fear that he may have been cheated out of many big titles.
Lets hope not. But though Sharapova has been caught, her case shows how difficult it could likely be to catch other cheaters. She was caught by a bit of a fluke, great carelessness. Her team didn't even know about what she was taking, and I'd assume other cheaters would protect themselves against whitleblowers as far as possible.