Manchester United midfielder Park Ji-sung will be sidelined until August at the earliest after undergoing knee surgery in the United States.

After failing to discover the exact nature of the injury picked up in the last minute of the Premiership victory over Blackburn last month, he opted to see Dr Richard Steadman, who has carried out a number of successful knee operations on soccer stars in the past.

Steadman complete the surgery this morning, and Park will now spend the next few months working on his rehabilitation before being examined again summer.

"Ji-sung Park has had a complicated cartilage operation that required an expert in his field," confirmed a United spokesman.

"He will be out for the remainder of the season and we will assess the situation again in August."

Not only will Park miss the end of United's Treble bid, he will also play no part in South Korean's Asia Cup campaign in July.