Manchester United’s Rio Ferdinand faces a lengthy spell on the sidelines as the club try to find the cause of his injury problems.
The defender will sit out Sunday’s match at Chelsea with a calf injury, which manager Sir Alex Ferguson suspects is related to a lower back problem.
“There has been no improvement,” said Ferguson. “We are having to look at something different.
The injury is likely to rule Ferdinand out of England’s friendly against Brazil in Qatar next week
“Usually you are back from a calf injury within two or three weeks,” added Ferguson.
“But there is no sign of recovery from this injury so we are looking at whether it is to do with his lower back.”
Ferdinand, who missed the first month of the season after tearing a thigh muscle in training, last played in the 2-0 defeat by Liverpool at Anfield.
Fellow centre-back Nemanja Vidic has a niggling calf injury but is expected to face Chelsea in the top-of-the-table clash at Stamford Bridge.