Sir Alex Ferguson felt Rio Ferdinand's performance in Manchester United's 1-6 home humiliation by Manchester City was the beginning of the end for the veteran defender.
Ferguson told his charges they had "disgraced themselves" in the dressing room and he took particular umbrage with Ferdinand, who he felt was responsible for the final goal, which was scored by David Silva.
"The last passage of play was a disgrace. It was comedy," Ferguson writes in his autobiography, which is released on Thursday.
"That game was a watershed for Rio.
"He used to show the attacker where to knock the ball and then take it off him. Now he was trying that with David Silva and wasn't able to beat him."
