The 24-year-old limped off during the first half of PSG’s 3-1 win at Montpellier on Wednesday.
PSG have five matches to play from February 4-19, with the France international missing the Bayern clash as well as their French Cup last-16 match against Olympique de Marseille.
“Following tests, Kylian Mbappe has suffered an injury to the left thigh at the level of the femoral biceps,” PSG said.
Defender Sergio Ramos was substituted during Wednesday’s match with adductor discomfort, but further tests will be carried out on Thursday to determine the extent of his injury.
PSG extended their Ligue 1 lead to five points on Wednesday and next host Toulouse on Saturday.