The former Stuttgart defender sustained medial ligament damage to his left knee while training with Germany ahead of the Wales encounter in Cardiff.

"My boot caught in the turf when I was making a tackle," Lahm was quoted as saying by Bayern official website.

"There was a huge impact when my left knee hit the ground, it really dug into the turf. I almost blacked out, and I feared the worst."

The 23-year-old is expected to be sidelined until early October if his recovery goes according to plan.

The news will come as blow to Germany coach Joachim Loew who is already without Chelsea midfielder Michael Ballack, Werder Bremen duo Torsten Frings and Tim Borowski as well as Bayer Leverkusen's Bernd Schneider.