Red Bull Salzburg have enforced a "team quarantine" and will not release players for international duty after three tested positive for Covid-19.
The club say the positive results came after their Champions League play-off with Maccabi Tel Aviv on Wednesday.
The players, who have not been named, are asymptomatic and in self-isolation.
"All international call-ups for Salzburg players in the next two weeks have been rejected," said Salzburg in a statement.
The Austrian club explained players who have tested negative will "only travel between their house, the training ground and match locations".
It means that several African nations will be missing Salzburg players for the October international window.
Zambian duo Patson Daka and Enoch Mwepu will not be able to travel to play in Chipolopolo's friendlies in Kenya on 9 October and then in South Africa two days later.
Sekou Koita will not be able to travel for Mali's commitments neither will Jerome Onguene for Cameroon, who have a friendly against Japan planned.
Also missing out will be Salzburg goalkeeper Cican Stankovic and defender Andreas Ulmer who had been called up by Austria for three matches during the October international window, while midfielder Dominik Szoboszlai had been selected for Hungary.
Israeli side Maccabi had 11 players missing for their 3-1 play-off defeat by Salzburg because of coronavirus.
Despite the missing players Salzburg thrashed TSV Hartberg 7-1 in the Austrian Bundesliga on Sunday, with Onguene, Koita and Daka all on the score sheet.