The Frenchman, a World Cup winner with France in July, tore his cruciate ligament and meniscus in his right knee after he scored an equaliser for Bayern and will undergo surgery later in the day, Bayern said in a statement.
The champions said they will also be without defender Rafinha for several weeks after the Brazilian partially tore a ligament in his left ankle in the same game.
The Bavarians, top of the league with three wins from three matches, are already missing winger Kingsley Coman, who was injured at the start of the season.
They kick off their Champions League campaign next week against Benfica in Lisbon.
(Reporting by Karolos Grohmann; Editing by Amlan Chakraborty)
