Eintracht Frankfurt midfielder Sonny Kittel is set for a lengthy spell on the sidelines after tearing the anterior cruciate ligament in his left knee.
The 22-year-old has struggled with injuries throughout his career and was dealt a fresh blow after lasting just 20 minutes of Saturday's 1-0 Bundesliga defeat at Werder Bremen.
No timescale has been put on an expected return for Kittel, but tests also showed damage to his medial collateral ligament.
"We are deeply shocked by the prognosis," Frankfurt coach Thomas Schaaf told the club's official website.
"We're terribly sorry that Sonny has suffered a serious knee injury after all the setbacks in his young career. Now one can only look ahead."
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