Hertha Berlin are worried that centre-back John Brooks could miss crucial parts of their preseason as they bid to qualify for Europa League.
Brooks finally cemented his place in the United States side during this summer's Copa America after first breaking on the international scene at the 2014 World Cup.
However, the U.S. defender missed the Copa third-place match against Colombia due to knee inflammation and there's a fear he may now miss the start of the new season.
Back in Germany, his hometown club Hertha Berlin are worried that the injury could serve as a blow for their hopes to qualify for the Europa League over two playoff rounds from late July onwards.