The diagnosis has been revealed for Bayern Munich captain Philipp Lahm, and it's not good.
The 31-year-old suffered the injury during a training session Tuesday, and his absence will now leave a massive hole for manager Pep Guardiola, who will be tasked with replacing one of the most versatile players on the planet.
For a squad that is already ravaged by injuries to some of its best and most influential performers, this will come as a serious test.