Manchester United midfielder Park Ji-sung has been ruled out for four weeks because of a hamstring injury.
The South Korea international, who recently returned from the Asian Cup in Qatar, injured his hamstring in training on Friday.
United manager Alex Ferguson said: "it was very unfortunate because it was his last kick of the ball in training as well. We were really looking forward to having him back after being away for a month at the Asian Cup. He'll be out for up to a month, which is a blow to us."
Man United lead the Premier League by four points from second-placed Arsenal.