Colin Cooper and David Beckham square up at the Riverside on Saturday (RossKinnaird/Allsport)

He is also undergoing 'lifestyle counselling' as part of his programme at The Priory clinic, in Altrincham, Cheshire.

The Republic of Ireland midfielder, who has rocked his United colleagues with attacks on some of them in the past week, is being seen as an out-patient.

He has had difficulty coping with United being knocked out of the Champions League following their quarter-final defeat by Bayern Munich two weeks ago, but the roots of his problems go further back than that.

Keane's treatment comes at the same time as a thinly disguised attack on him by his team-mate David Beckham.

Beckham, the England captain, hit out over Keane's claims of complacency in the United dressing room and the Irish-man's public slating of his United team as 'average'.

Beckham said: 'We have never been a side to come out in the papers saying things about each other or other players. This is a great team. We have won seven championships in nine years and that's not the sign of an average side.

'There are some players who've not done as well as they can this season but you should always stick together.'

Keane missed the 2-0 victory by United at Middlesbrough, the club saying he had a bad back. He was also absent as the Republic of Ireland beat Andorra 3-1 in a World Cup qualifier last week.

Keane had particularly wanted to win the Champions League this season after missing the dramatic final victory over Bayern two seasons ago because of suspension.

He has also had difficulty coping with being one of the best-paid footballers in Britain with a pay deal giving him a weekly £70,000.

One of the areas of counselling the staff at the Priory are looking at is how he spends his money and the pressure he feels under to justify his enormous salary to his peers in Ireland where he grew up, many of whom would take five years to earn Keane's weekly wage.