(CNN) -- Manchester United manager Alex Ferguson has admitted an English Football Association (FA) charge of improper conduct after he publicly questioned the fitness of referee Alan Wiley.
Ferguson made the remarks after his side's 2-2 home draw against Sunderland in the English Premier League on October 3, claiming 49-year-old Wiley could not keep up the pace of the game.
He also compared him unfavorably with referees in other top European leagues who the Scot claimed were as "fit as butcher's dogs."
Official match statistics appeared to refute Ferguson's claim and he later apologized to the referee, but it was not enough to prevent the FA taking action.
"I apologize to Mr Wiley for any personal embarrassment my comments may have caused and to the FA for going public with my views.
"In retrospect I accept that they could be deemed as expressing those views in an inappropriate form. It was never my intention to bring the focus of intense media interest on Mr Wiley."
Ferguson has requested a personal hearing and faces a fine or a touchline ban, with the referees' union Prospect saying it should be lengthy.
The 67-year-old Scot was again in the headlines this weekend for his criticism of a referee.
In the aftermath of his side's 2-0 defeat to arch-rivals Liverpool, Ferguson highlighted the lack of experience of Andre Marriner.
The United manager was furious that Marriner did not send off Jamie Carragher as he pulled back Michael Owen near the end of the match at Anfield as his side sought an equalizer.