This sparring partner thing is a typical klitschko fanboy logic. But laughable. But otherwise isn't total stupidity Mccall's case proves this. He was an incredible good Mike Tyson sparring partner and later a Lennox Lewis destroyer.
There was a thread on this site years ago that got deleted about Haye possibly fighting Johnson in one of his first HW fights. There were Klitschko fans calling Johnson a complete bum and disgraceful opponent. CHEF even said something like "I knew Haye was gonna pick a tomato can but he really picked the field for this one.":roflatsch
Facts: Johnson was ranked in the top ten by ring magazine before and at the time of the fight. He was undefeated, and in his prime. No one is saying he was as good as Sanders, Peter, Solis, etc...