Nemanja Vidic is likely to miss Saturday's Barclays Premier League title showdown with Chelsea at Stamford Bridge.
The Manchester United defender received hospital treatment for a stomach problem on Tuesday and was forced out of his side's goalless draw with Barcelona on Wednesday night.
United manager Sir Alex Ferguson confirmed Vidic had a stomach infection and is unlikely to return against Chelsea.
"He was 24, 36 hours without eating," said the United manager.
"He had some soup this afternoon, but wasn't ready to play. I don't think he'll be ready for Saturday, that's the situation, it's a stomach infection, (although) we don't know what kind of infection it is.
Ferguson added: "Yesterday before training, he had very severe stomach pains, so we sent him off to a hospital only about a mile away.
"We felt that was the best place for him to go. He was kept in until late at night and then they let him go."