England captain Ferdinand doubtful for World Cup due to knee injury

Rio Ferdinand's World Cup is hanging in the balance after the England captain left hospital on crutches following a knee injury he sustained in training this lunchtime.

Ferdinand went down in agony and was sent for a scan by manager Fabio Capello amid fears he had suffered ligament damage.

The Football Association have still to make an official comment on the Manchester United defender's injury but at this stage it looks possible he has suffered a major injury.

The 31-year-old center back was injured while defending against striker Emile Heskey during England's first full training session in South Africa, barely a week before England's opener against the United States in Rustenburg on June 12.

Tottenham defender Michael Dawson, who was cut from the preliminary 30-man squad on Tuesday, has been put on standby as a possible replacement for Ferdinand.

Under FIFA rules, players can be replaced up to the day before the opening game.

"The bad news is in the last moment of the training, Rio suffered a problem with the knee," England coach Fabio Capello said.

"It came from a minor tackle during the training. How bad is it? We will have to wait and see."

If Ferdinand is ruled out of the tournament, Matthew Upson or Ledley King, who has chronic knee problems, would likely take his starting spot in central defense alongside John Terry.

Source: Xinhua