Borussia Dortmund are set to miss their midfielder Nuri Sahin for eight weeks after he underwent a left knee operation on Wednesday.
The 25-year-old Turkey international has been suffering from inflamed tissue in the knee for some time.
Sahin last featured for the Westfalendians in their 2-0 defeat by Bayern Munich in the German Cup final early June.
Dortmund activated the buy-back clause in Sahin’s contract, which allowed him to rejoin the club from Real Madrid for a fee in the region of 7 million euros.
Sahin is expected to remain on the sideline till October and will miss Bundesliga matches at Mainz and Schalke, as well as home games against Freigburg this weekend and Stuttgart in three weeks’s time.
He is also ruled out of their Champions League opener at home to Arsenal on September 16 and away at Anderletch on October 1.