David Alaba is in doubt to face Olympiacos in the Champions League on Tuesday, Bayern Munich have confirmed.
The Austria international took a blow to his ankle during a 3-1 win away to Schalke on Saturday and could be forced to sit out the meeting with the Greek champions at the Allianz Arena.
"The use of David Alaba is a question mark," Bayern announced via their official website.
"The left-back had to be substituted in the 83rd minute of the 3-1 win over Schalke on Saturday after a foul.
"He withdrew with an injury to his left ankle that was looked over by team doctor Volker Braun on Sunday. Whether Alaba can play against the Greek champions will depend on the healing process over the next few days."
Alaba has made 20 appearances in all competitions so far this season.