The Borussia Dortmund attacker suffered a torn ligament during his side's 0-2 loss at Borussia Monchengladbach, while teammate Sven Bender is struggling with with a muscular problem.
Furthermore, Bayer Leverkusen's Lars Bender picked up a thigh injury in his team's 1-1 draw with Bayern Munich on Saturday.
The three players join Marcel Schmelzer, Ilkay Gundogan, Lukas Podolski, Mario Gomez and Miroslav Klose on Germany's injury list.
Meanwhile, BVB confirmed on Monday that Jonas Hofmann injured his knee in training, thus ruling himself out for at least 10 days.
One of those to benefit from the unavailability of so many first-team regulars is Hamburg's Heiko Westermann, who could now feature in the qualifying matches against Ireland, on Oct. 11, and Sweden, on Oct. 15.