Borussia Dortmund's head of player department Sebastian Kehl said on Thursday they could stop their players from featuring for Germany in the Nations League next month due to coronavirus worries.
Joachim Loew's side travel to Ukraine on October 10, a country which is classed as a Covid-19 red zone due to its high number of cases.
"We're working to find solutions, but we reserve the right to not make the players available, as long as there's no rule allowing the players to play immediately after they return," Kehl told specialist magazine Kicker.