Germany coach Joachim Loew has admitted he is concerned by Mario Gotze's latest set-back as the midfield star has suffered with consecutive injuries since April.
The 21-year-old tore his hamstring in April for former club Borussia Dortmund, then suffered an ankle strain during last Friday's UEFA Super Cup final for Bayern Munich in their penalty shoot-out win over Chelsea in Prague.
Having only made his comeback in August, Gotze played just four games, including 128 minutes in the Bundesliga, before suffering the new injury when Chelsea's Ramires trod on his ankle, which led to the Brazilian's red card.
Gotze, who made the last of his 22 appearances for Germany in March, returned from the Czech Republic in a plaster cast and is expected to miss the rest of the month, including Germany's World Cup qualifiers against Austria on Friday and minnows Faroe Islands next Tuesday.
With a view to next June's World Cup in Brazil, Germany boss Loew has said Gotze will need time to find his form and consistency.
"It is a huge pity that he is injured again, having just slowly got into a rhythm after his previous injury," said Loew, whose Germany team is five points clear at the top of their qualifying group.
"He needs to be allowed to find his form again," he added who described Gotze as an "exceptional" player.
"In a World Cup season, it is important to get some consistency and I hope he finds it."
Gotze faces a race to be fit for Germany's next World Cup qualifiers against the Republic of Ireland in Cologne on October 11 and four days later against Sweden in Stockholm.
After Gotze cost Bayern 37 million euros (US$48.53) from Dortmund, Munich chairman Karl-Heinz Rummenigge said the attacking midfielder will become a major star.
"He is on the way to becoming a world star and he will take the next step with Bayern Munich," Rummenigge told SID, an AFP subsidiary.
"He will give us the piece of quality which will ultimately make us successful."