Paris Saint-Germain fear they could be without Thiago Silva for some time after he suffered a hamstring injury.
The Brazil defender was forced off after 16 minutes of Sunday's 1-1 draw with Monaco in Ligue 1 and coach Laurent Blanc said after the game: "I think we have lost him for a while."
A club statement on Monday revealed: "Today's MRI scan for Paris St Germain defender Thiago Silva has confirmed a muscular injury to his left hamstring.
"The duration of the Brazil international's unavailability will be specified later, depending on the evolution of his injury."
With Alex also having been sidelined by injury of late, PSG are likely to field a third Brazilian, Marquinhos, and Thiago Silva's replacement against Monaco Zoumana Camara when they travel to Valenciennes on Wednesday.