Bayern Munich defender Jerome Boateng suffered a knee injured in their 4-2 victory over Borussia Dortmund in the Bundesliga on Saturday but the extent of the damage is not yet known, coach Hansi Flick said.
The central defender went down injured without an opponent involved when his left foot seemingly got stuck in the grass and he was taken off in the 70th minute.
"When he came off he told he had turned his knee," Flick told reporters. "We do not have a clear diagnosis yet. We will have to wait for that and see what happens next."
Boateng, a 2014 World Cup winner, has earned back a starting spot this season after he was widely expected to leave last summer. Germany coach Joachim Loew is even considering calling him up again after he was dropped two years ago.
Bayern, who have won six titles in the past nine months, are top of the Bundesliga, two points clear of second-placed RB Leipzig.
The Bavarians, defending champions, face Italy's Lazio in 11 days in their Champions League round of 16 second leg.
(Reporting by Karolos Grohmann, editing by Ed Osmond)
