Alphonso Davies is suspected to have suffered a hamstring strain and now faces an anxious wait to learn whether he will be fit to feature for Canada at the World Cup.
Davies was forced off in the 64th minute of Bayern Munich's thrilling 3-2 win at Hertha Berlin on Saturday, a result which – at least temporarily – moved them ahead of Union Berlin at the Bundesliga summit.
The left-back, who plays in attack for Canada, was seen clutching his right hamstring as he walked gingerly from the field, causing concern for his country ahead of their World Cup opener against Belgium on November 23.
Speaking after Bayern's fourth league win in a row, concerned coach Julian Nagelsmann said: "In terms of that injury, we have to wait until tomorrow. The doctor says there is at least one fibre tear.
"Wait and see what comes out tomorrow."
After Eric Maxim Choupo-Moting's brace allowed Bayern to build on Jamal Musiala's opener, Hertha fought their way back into the match at the end of a remarkable first half, and Nagelsmann was under no illusions as to the importance of the win.
"It wasn't an easy game. We had a couple of good moments in the first half; it was a wild game," he said.
"We led 3-0, but we didn't have any clear actions. The lead was generally a bit too much. Then we got into a phase in which we didn't manage much.
"It got exciting again. In the end, we threw everything in; it was a game that you have to win."