Man United's Ferdinand ruled out of Chelsea match

MANCHESTER, England (AP) Rio Ferdinand has been ruled out of Manchester United's meeting with Premier League leader Chelsea on Sunday because of what the club suspects is a back injury.

The England defender has sat out the defending champions' past three games with a calf problem but manager Alex Ferguson says the injury may have been misdiagnosed.

Ferguson says "we are having to look at something different because usually you are back from a calf injury within two or three weeks."

United trails Chelsea by two points at the top of the standings.

Updated November 6, 2009