Xherdan Shaqiri has become the third Liverpool player in a week to test positive for coronavirus.
The 28-year-old had travelled to Switzerland for a friendly against Croatia, and Nations League games against Spain and Germany, but will now not be involved as he is self-isolating, the Swiss Football Association has announced.
Last Tuesday the Reds' new signing Thiago Alcantara tested positive for Covid-19 and on Friday forward Sadio Mane also went into self-isolation after his positive test.
"Xherdan Shaqiri has tested positive for Covid-19. In consultation with the health authorities, he is in isolation," said a statement from the Switzerland Football Association.
"The strict protective measures and requirements of UEFA for national teams in accordance with the 'UEFA return to play protocol' have been strictly adhered to since the move began.
"Based on this, clarifications are currently under way with the local health authorities about how to proceed."
Liverpool had hoped to offload Shaqiri, who has been limited to just 82 minutes of action since January 11 – 75 minutes of which came in the Carabao Cup at Lincoln – because of injury, in the recent transfer window but interest from a couple of Italian clubs failed to materialise into an acceptable bid.