United confirmed on Wednesday that the Reds' medical staff are monitoring the injury and would await the results of a scan and further assessment before the extent of the problem is known.
Sir Alex Ferguson said on Tuesday night that it was too early in the aftermath of the Bayern match to assess the severity of the injury. "We’ll just have to wait and see," he said. "Hopefully it’s not too serious. He might be doubtful for Saturday against Chelsea but we don’t know for sure."
ManUtd.com will be first with any official news on Rooney's injury.