Eintracht Frankfurt will be without captain Pirmin Schwegler for a large part of the season after he suffered torn knee ligaments on international duty with Switzerland.
Shwegler's injury happened when he turned awkwardly in training, with the national team's doctor confirming that the ligaments are damaged.
A Swiss knee specialist Doctor Roland Biedert said that surgery is required, which will take place on Saturday.
The 27-year-old has played 110 times in the league for Frankfurt.