ALEX Ferguson has confirmed Manchester United winger Antonio Valencia is facing four weeks out of action after injuring his hamstring against Ajax last night.

Valencia had only been introduced as a second-half substitute and helped set up Javier Hernandezs match-clinching goal, Uniteds second.

However, the South American was injured in the build-up and was immediately taken off by manager Ferguson.

“He has a hamstring injury, unfortunately,” Ferguson said. “It will be four weeks.”

Ferguson admitted it was a significant setback given the brilliant form Valencia has been in recently. “It is a bad blow for us,” he said.