England are sweating on the fitness of skipper and key defender Rio Ferdinand with their opening World Cup match barely a week away.

The Manchester United player suffered a knee injury during the final minutes of England’s first major training session since arriving in South Africa yesterday.

Ferdinand immediately went to hospital to undergo a scan but England coach Fabio Capello’s concern is such he has called up Tottenham’s Michael Dawson on stand-by.

England can ill afford to be without the services of Ferdinand despite an injury-hit season with United.

He is set to participate in his fourth World Cup and has vast experience to call upon.

Capello confirmed: “The bad news is in the last moment of the training, Rio suffered a problem with the knee.

“He has just gone to hospital for a scan. We hope it will not be so bad an injury but we have Michael Dawson on call.

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

The alternatives in the squad are Matthew Upson and Ledley King who looked far from convincing in the recent friendly with Mexico at Wembley.

Dawson was named in Capello’s initial party of 30 for the finals but was excluded from the final 23.