Borussia Dortmund midfielder Ilkay Guendogan is expected to be out for at least a month after aggravating a back injury, last season's Champions League runners-up said on Tuesday.
The 22-year-old Germany international picked up the injury during a 3-3 draw against Paraguay on Aug. 14. His participation had been in doubt because of the injury and he needed injections to play before being taken off midway through the first half.
"It will be a rehabilitation period of what looks to be a month," said Dortmund team doctor Markus Braun.
This means he will miss Germany's World Cup qualifiers against Faroe islands and Ireland on Sept. 11 and 15 as well as the start of the Champions League group stage.