The 32-year-old defensive midfielder -- capped 26 times by Germany -- tore ligaments in the ankle during the 4-2 win over Hertha Berlin last Saturday.

"It is very frustrating obviously but I will do everything I can to return as quickly as possible," said Rolfes, who has played in all five of Bayer Leverkusen's official matches this season.

Rolfes, who has been a pivotal figure as Leverkusen won all three of their Bundesliga games the only side to do so, will not only miss several league matches but also their opening Champions League group game with French Ligue 1 runners-up Monaco on September 16.