Stuttgart - Arne Friedrich is a doubt for Germany's upcoming World Cup qualifiers against Liechtenstein and Wales after picking up a thigh strain in Hertha Berlin's 2-0 loss Saturday to VfB Stuttgart.

"I wasn't able to walk or jump anymore," said Friedrich, who was replaced after 25 minutes and will now undergo a scan Sunday to assess the seriousness of the injury.

Germany play Liechtenstein next Saturday before taking on Wales four days later. (dpa)