David Alaba will miss up to three weeks with the thigh tear he suffered on Saturday, Bayern Munich head coach Niko Kovac has confirmed.
Austria international Alaba was forced to skip the Bundesliga draw against RB Leipzig after injuring his left thigh during the warm-up at the Red Bull Arena.
Kovac's timeline potentially rules the left-back out of action until after the October international break.
"David will be out for two, maximum three weeks," Kovac said.
"Obviously, David is a really important player for us. Unfortunately he's going to be out for a couple of weeks but Lucas Hernandez won the World Cup in that position.
"He has a different interpretation of how to play at left-back than David does but he does a very good job.
"Alphonso [Davies] can play in that position, that's actually why we fielded him against Leipzig. He didn't play as a left-back but we fielded him so that he could work together with Lucas. Tomorrow is a Champions League game, it might be a bit different."
One man who could benefit from Alaba's injury is Jerome Boateng.
The centre-back, routinely linked with a move elsewhere during the transfer window, stepped into the starting XI at late notice against Leipzig and impressed Kovac.
"I keep saying the same thing about Jerome Boateng - he's a part of this team and as a part of this team I treat him like everyone else," the Bayern boss said.
"Everyone has the right to play here. Jerome didn't play a lot in the last couple of weeks, however, on Saturday he had to play from the first moment to the last and it was a class performance. I want to emphasise that.
"Of course, I have a lot of very good players. It was his first game [in the Bundesliga] and he played 90 minutes. That's a different rhythm from someone who plays once or twice a week.
"We'll have to see how he copes. I am happy with him and he will get chances to play, that's all I can say really."