Raphael Schaefer will undergo scans to determine the extent of the injury that forced him out of Nuremberg's 0-0 draw with Augsburg.
The goalkeeper was substituted off at the interval with an Achilles problem, paving the way for teenager Patrick Rakovsky to make a rare appearance on Sunday.
Rakovsky nearly allowed Augsburg to score the opening goal when he failed to collect a corner, but he stood stall before denying Aristide Bance a golden opportunity.
The stalemate ended a four-match losing streak for Nuremberg, who slipped to 15th, two points above Augsburg and the relegation zone.
"At least we stopped the bad run somewhat," Schaefer said.
"Of course it wasn't a good game. You can see how insecure the team is at the moment."
Rakovsky said he was pleased with his performance but wished Schaefer a speedy recovery.
"The coaches and players have supported me and the fans behind me applauded me, which made me happy," he said.
"I made some mistakes but I'm glad that no goal was scored. We fought right to the end.
"On the bench, of course, you always want to get some time, but I hope that Raphael is not seriously hurt."