Sir Alex Ferguson has apologised to referee Alan Wiley for any embarrassment caused by his sustained attack on the official's fitness after last week's encounter between Manchester United and Sunderland at Old Trafford.

Immediately after the 2-2 draw Ferguson questioned whether Wiley had the necessary fitness to take charge of such a keenly contested Premier League match and claimed at periods during the game he needed a rest.

Watch highlights of the Man Utd 2-2 Sunderland game

The attack outraged referees, who have put the Football Association under pressure to take tough action when they review the case, having now asked Ferguson for an explanation.

But the Scot has already decided it was not the wisest choice of words.

"I apologise to Mr Wiley for any personal embarrassment my comments may have caused and to the FA for going public with my views," said Ferguson. "In retrospect I accept 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 and I will apologise to him personally when I return from an overseas trip during the international break."

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