Lahm, 30, underwent checks upon the team's return to Munich on Thursday and will miss their next two league games.
"He will miss the upcoming games against Eintracht Braunschweig (on Saturday) and Augsburg," the club said in a statement.
Bayern, four points clear at the top of the Bundesliga, are already missing several key players through injury, including Bastian Schweinsteiger, Franck Ribery, Claudio Pizarro and Xherdan Shaqiri, as well as long-term absentee Holger Badstuber.
- Sports & Recreation
- Eintracht Braunschweig
- Bastian Schweinsteiger
- Franck Ribery