COVID-19 has emerged as Liverpool's main threat to retaining the Premier League title, with Sadio Mane the latest to contract the virus.
The Senegalese forward started Sunday's 3-1 win over Arsenal, but was absent from Thursday night's Carabao Cup exit to the same opposition.
Liverpool say Mane has displayed minor symptoms of the virus but feels in good health overall.
He's the second member of the squad to contract coronavirus.
Recent signing Thiago Alcantara will miss this weekend's trip to Aston Villa as he continues to isolate. His positive test was confirmed on Tuesday.
Liverpool say they will continue to follow all protocols, and Mane will isolate for a period of time.
Earlier this week, Reds assistant coach Pep Lijnders revealed the club offers private testing, on top of the Premier League's mandatory PCR screening.
Earlier in the day, Liverpool manager Jurgen Klopp had expressed his concern about players potentially contracting the virus while on international duty next week.
"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," he told his press conference.
"So I am slightly concerned because it is difficult to be in contact with all FAs 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."
In better news for the champions, captain Jordan Henderson could be involved in Sunday's game at Villa Park.
The midfielder hasn't featured since being substituted at half-time in the 2-0 win at Chelsea last month.
Klopp said on Friday, "Hendo will be part of parts of the training today. He will start with warming up, maybe some passing, maybe some rondos, we will see as a first step.
“He has absolutely no muscle issues. It is all fine, he is not injured anymore, so now we have to make sure he can make the next step. What that means for the weekend, I don’t know."
Henderson was named in Gareth Southgate's England squad for their upcoming games with Wales, Belgium and Denmark.