Träsch ruled out of Germany qualifiers
The 23-year-old Stuttgart player twisted his left ankle during training on Tuesday, making him the second holding midfielder after Bastian Schweinsteiger to be ruled out of their Group A games in Austria on Friday and Azerbaijan on June 7.
"We have decided not to nominate another player because we trust the current squad," coach Joachim Löw said.
Löw had already seen strikers Marco Reus and Miroslav Klose ruled out with injuries, while midfielder Sami Khedira, who has recovered from a thigh muscle injury, is battling to be fit in time for the matches.
Toni Kroos is likely to play as the holding midfielder in both matches.
Germany lead the standings on 15 points, with five wins from as many matches, and are well on course to qualify for next year's finals being co-hosted by Poland and Ukraine.