Borussia Dortmund are waiting on the fitness of Mats Hummels for Saturday's key Bundesliga showdown with Bayern Munich after he limped out of Germany's 1-0 friendly win over England.
Having come on as a second-half replacement at Wembley, centre-back Hummels lasted just 20 minutes on Tuesday, four days before the top of the table clash against European champions Bayern at Dortmund's Westfalenstadion.
"He twisted his ankle after a header. We haven't had an exact diagnosis and I hope that it isn't bad," said Germany coach Joachim Loew.
With European champions Bayern four points clear in the league, Dortmund are already without Hummel's centre-back partner Neven Subotic, who is out for at least six months with a knee injury.
Subotic's possible replacement, ex-Germany defender Manuel Friedrich, 34, who was released by Bayer Leverkusen at the end of last season, picked up an injury in a practice match on trial with Dortmund on Tuesday, according to German daily Bild.
Borussia coach Jurgen Klopp is also waiting on the fitness of left-back Marcel Schmelzer, who played the first-half against England.
"He had a problem with his calf, his substitution was a precautionary measure," said Loew.
Bayern coach Pep Guardiola was also presented with an injury concern from the England-Germany match as centre-back Jerome Boateng was also taken off after halftime, due to a minor heel injury, "we didn't want to take a risk with him," added Loew.