Speaking on the Beast Mode On podcast with Adebayo Akinfenwa, Clattenburg said: "Sir Alex would send one of his players in, not to influence that decision because he knew referees weren't going to change their mind, but it was the next one, and it was the next one. So you would make a decision and then you would have Rio Ferdinand, Roy Keane, then they would send somebody else and it would be one after the other after every decision. Chipping away, chipping away, it was mind games.
"It never shaped [decisions] because I always wanted to get the next one right, I used to pride myself on getting everything right, but unfortunately you can’t and that’s human fact. There’s nobody perfect in football... but what it did was I would go away and analyse myself and I would go: ‘How can I manage that better? How can I manage them without becoming arrogant or pissing them off?’
"So the way I started to handle it in the future, when they would come in one by one, I would just say: ‘Go and tell your gaffer to f*ck off', and tell them what's happening… Man Utd were the ones because there weren’t many doing it at that point.
"I remember Rio Ferdinand once, I said to Rio, ‘tell him to f*cking behave himself’, and he says, ‘I'm not telling him. I'm not telling him’!"