McClaren wrote in the Daily Express: "One of Sir Alex Ferguson's main strengths is that he is never satisfied. He has been a fighter all his life and he wants fighters in his team. And if you are not cut from that sort of cloth, he will get rid of you, as simple as that.
"It would have been fascinating being a fly on the wall at the Carrington training ground yesterday morning, after Sir Alex and his side had just secured a 20th title.
"I have no doubt he would have gone into the canteen and shouted out for a cup of tea. One of the dinner ladies would fire back, 'Get it yourself, we're not slaves here you know'.
"That tells you all you need to know about Manchester United as a football club; there are no stars or hero worship, it is just a club based on sound principles and that goes for everyone, from the manager to the players, to the young academy kids and to the cleaning ladies and dinner staff. It is a club run on those lines.
"There is no special treatment for anybody in that canteen. You are all equal."