Sir Alex Ferguson has confirmed Manchester United winger Antonio Valencia is facing four weeks out of action after injuring his hamstring in 2-0 win over Ajax.
The winger sustained the knock soon after coming on as a second half substitute for goalscorer Ashley Young at the Amsterdam ArenA.
Despite being involved in the build-up to United's second goal of the game, which was scored by Javier Hernandez, Valencia was immediately taken off the field after pulling up in midfield.
Ferguson has confirmed Valencia now faces up to a month on the sidelines which is a blow for United as the Ecuador star has been in superb form in recent weeks
"He has a hamstring injury unfortunately," Ferguson said. "It will be four weeks."
"It is a bad blow for us."