Per Mertesacker will not return to the Werder Bremen defence for their derby with Hanover tonight, as had been initially expected.
The 25-year-old fractured his eye socket playing for Germany a fortnight ago, and had expected to play for his Bundesliga side wearing a protective mask tonight.
However, a lack of training during his injury lay-off means Mertesacker is not match-fit.
"I had a ten-day lay-off without training, and I don't feel ready," he explained. "I just have to wait for the green light from doctors."
It means Werder are without their two main centre-backs, as Brazilian Naldo is also out injured. That means a likely start for Frenchman Mickael Silvestre.
In next month's UEFA EURO 2012 qualifiers, Germany host Turkey on 8 October and face Kazakhstan in Astana four days later.