However, Fergie has revealed that Rooney's injury is not too serious and that the United striker should be fit to play in the friendly match against Portsmouth in Nigeria on Sunday night.
"Wayne got a knock above the knee and a dead leg just after half-time and that's why we took him off, but he should be okay for Sunday," the United boss has told the clubs official website.
"Gary Neville and Mikael Silvestre will both start, as will Scholes and Tevez. Only Danny Simpson and John O'Shea won't play."