The Croatian football federation says midfielder Marcelo Brozovic has tested positive for the coronavirus.
It says Brozovic has been isolated from the rest of the team which is to play Sweden in Stockholm on Saturday in a Nations League game.
The 27-year-old Brozovic plays for Inter Milan.
Defender Domagoj Vida was pulled out of Croatia's friendly match against Turkey on Wednesday after a positive test.
Earlier, the Swedish football federation said defender Carl Starfelt had been isolated after testing positive for COVID-19.
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