Manchester United midfielder Park Ji-Sung has flown to meet US knee specialist Dr Richard Steadman for a diagnosis on the injury which has ended his season.
The South Korean star has not featured for United since the home win over Blackburn on 31 March.
Although Alex Ferguson initially suggested Park would be back in action within a couple of weeks, the timescale proved inaccurate, with the 25-year-old struggling to take any part in training.
These were denied by chief executive David Gill at a news conference in Seoul to publicise United's forthcoming Far East tour.
However, Gill admitted the exact length of Park's absence was not known and the player had remained in the United States for further tests.
Steadman has a history of successful knee operations.
Former United striker Ruud van Nistelrooy is among a host of players to have benefitted from Steadman's care and the surgeon also operated on Michael Owen when the England star ruptured his cruciate ligaments at the World Cup.
But Alex Ferguson has confirmed today: 'We have not been able to get to the bottom of it, so we have sent him to the best specialist in the world. Unfortunately, it puts and end to his season.'
