Arsenal midfielder Mesut Ozil has been sent for a scan after missing Germany training with a knee injury.
Ozil is part of the World Cup winners' squad for the upcoming European qualifiers against Poland and the Republic of Ireland.
But the German Football Association, GFA say he reported for duty with "knee problems" and has now left the Frankfurt camp for Munich, where he will undergo further tests.
"There is some problem with the left knee. We cannot say more at this moment. We will have to see how it goes," said Germany team spokesman Jens Grittner.
"If there are any further personnel developments during the day we will let you know."
Ozil played the full game on Sunday as Arsenal were beaten 2-0 at Chelsea, the sixth time in six English Premier League starts he has completed all 90 minutes.
Any spell out would further deplete an Arsenal squad already missing Olivier Giroud, Mathieu Debuchy, Aaron Ramsey, Mikel Arteta and Theo Walcott.