GLASGOW, June 12: Roy Keane, the midfielder who was instrumental in Manchester United's dominance of English football throughout the 1990's, has announced his retirement from football because of injury.

The Irish international, who finished his career by helping Celtic to the Scottish league title, made the announcement on Monday after receiving doctor's advice to quit, six months after leaving United following an acrimonious bust-up with Sir Alex Ferguson.

“Having received medical advice from my surgeon and the Celtic club doctor, I feel my only option is to retire,” Keane said in a statement.

The statement did not specify the nature of the injury which has forced Keane to call it a day but the Irishman had been plagued by recurring hip problems in the last few seasons of his illustrious career.

Celtic manager Gordon Strachan, who had been hoping that Keane would be able to play for another season, paid tribute to ‘one of the greatest ever players to grace the game of football.’

”It was fantastic that we were able to bring him to Celtic and it has been a privilege to work with him,” Strachan said.

“Even in his short time with the Club, Roy made a great contribution and played an important part in bringing success to the club last season.

“We were delighted to make Roy?s dream come true when we signed him for Celtic and we were happy when he made our dream come true, by helping us to win the title.

“While we would have very much liked Roy to continue for the remainder of his contract, everyone at the club fully understands and respects the decision which he has made.

“Roy's retirement will be a loss to Celtic and, of course, a loss to football in general. We would all like to wish Roy and his family all the best for the future. Roy will always be welcome at Celtic Park.”

Both Strachan and Celtic Chief Executive Peter Lawwell emphasised that the Scottish champions would now have to look at strengthening their midfield as they prepare for the defence of their title and next season's Champions League campaign.—AFP