Hamburg defender Marcell Jansen has been forced to withdraw from the Germany squad for their upcoming World Cup qualifiers with Russia and Wales.
Jansen picked up a thigh injury during Hamburg's 2-1 win over Energie Cottbus on Sunday.
The 22-year-old is expected to be sidelined for over a fortnight and may not be fit for their next Bundesliga fixture either.
"The availability of Marcell Jansen against Schalke in two weeks is questionable," said Hamburg's team doctor Oliver Dierk.
Germany coach Joachim Low has yet to decide if he will call up a replacement for Jansen.