Borussia Dortmund will be without Germany midfielder Ilkay Gundogan for at least another four weeks, ruling him out of next month's World Cup qualifiers against Austria and Faroe Islands.
The 22-year-old has been sidelined since aggravating a back injury in Germany's 3-3 friendly draw against Paraguay on August 14 and an MRI scan on Monday revealed he has a strain in the lumbar region and will be out for another month.
It means Gundogan will miss Germany's World Cup Qualifier against Austria in Munich on September 6 and away to Faroe Islands in Torshavn four days later, as well as at least Dortmund's next three league matches.
Having joined from Nuremberg in 2011, Gundogan has risen to become first choice defensive midfielder for Dortmund and has put pressure on Bayern Munich's Bastian Schweinsteiger and Real Madrid's Sami Khedira for their places in the national side.
His contract expires in June 2015, but Dortmund are eager to extend Gundogan's deal.
"I believe that he will stay," said Dortmund's CEO Hans-Joachim Watzke.
"At this stage of his career, he knows what he has at Borussia Dortmund."