Liverpool's Sadio Mane has tested positive for coronavirus and is currently self-isolating.
Mane, who started and scored in Monday's 3-1 victory over Arsenal, has displayed minor symptoms of the virus but feels in good health overall, according to Liverpool.
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Liverpool team-mate Thiago Alcantara tested positive for coronavirus earlier this week.
"Sadio Mane has tested positive for Covid-19 and is currently self-isolating according to the necessary guidelines," the club said in a statement.
"The forward, who started and scored in Monday's 3-1 victory over Arsenal, has displayed minor symptoms of the virus but feels in good health overall.
"However, like with Thiago Alcantara, Liverpool Football Club are - and will continue to - follow all protocols relating to Covid-19 and Mane will self-isolate for the required period of time."
Thiago missed the Arsenal game after his own positive test and he and Mane will be absent for Sunday's Premier League trip to Aston Villa - live on Sky Sports.
Manager Jurgen Klopp will hope to have both players available when the Reds return to action after the international break in October 17's Merseyside derby at Everton.
Mane, 28, has been in fine form this season, scoring both goals in Liverpool's win over Chelsea before also netting against the Gunners.
His enforced isolation will also affect his international commitments after Mane was named in Senegal's squad for their upcoming friendlies against Morocco and Mauritania.
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Klopp concerned over international break
Earlier on Friday, Klopp admitted he is concerned about the prospect of releasing Liverpool players to international duty during the ongoing coronavirus pandemic.
Klopp takes his side to Villa Park on Sunday evening before a 13-day gap in the domestic fixture list in which the vast majority of his squad will be playing for their national teams.
His concerns about that situation are based around the fact the players will travel to countries where protocols around coronavirus have not been made clear, and also that players will be expected to return to league action on the Saturday after the midweek international fixtures.
"I don't want to sound disrespectful about how other countries are doing it but this is the place that we know and we know how we are dealing with it," said Klopp.
"So I am slightly concerned because it is difficult to be in contact with all FAs (football associations) all over the world.
"I understand it, I really understand how difficult the situation is but it's not exactly perfect, the information we get from certain FAs.
"As a football club you are pretty alone in these moments, we send the players away and then we have another challenge because we have to play a Premier League game on a Saturday after they have travelled from, maybe Peru, on the Thursday or Friday.
"You have to make sure you bring the players home in the quickest and safest way and then we have to see how they are before we try to get a result on the Saturday."