Real Madrid midfielder Fernando Gago will be out of action for a month, the club confirmed on Thursday.
The Argentina international had to be substituted after just over half an hour of Madrid's Champions League victory over BATE Borisov on Wednesday and medical tests have revealed the 22-year-old has injured a muscle in his left leg.
A statement on the club website read: "Medical tests this Thursday have diagnosed that the Argentinian is suffering from a Grade II fibrilar tear in the femoral biceps of the left muscle.
"The time estimated for his layoff is four weeks."
Gago will miss the Primera Liga games against Racing Santander, Sporting Gijon, Real Betis, Espanyol and Atletico Madrid, as well as the Champions League ties against Zenit St Petersburg and possibly Juventus.