Roberto Firmino, Joel Matip, and Alisson Becker are out of today’s match with Chelsea after testing positive for COVID-19

In addition to Alisson Becker, Roberto Firmino and Joel Matip, the Liverpool trio have been ruled out of Sunday’s Premier League trip to Chelsea after testing positive for COVID-19, according to the club. Liverpool’s manager Jurgen Klopp will also miss the game after testing positive on Saturday, with his assistant Pepijn Lijnders taking charge at Stamford Bridge.
A number of other players in the team were subsequently tested and found to be negative.

https://www.liverpoolfc.com/news/alisson-firmino-and-matip-return-suspected-positive-covid-19-tests

Virgil van Dijk, Thiago Alcantara, Fabinho and Curtis Jones have been out of action for the past few weeks after having positive tests. They have started training again recently. A point behind second-placed Chelsea, Liverpool are third in the league table with 41 points from 19 games.
Three players, as well as some staff, had tested positive for the virus on Friday, but Klopp said it is too early to ask the Premier League for a postponement. At Stamford Bridge, Pepijn Lijnders will be in charge in place of Jurgen Klopp, who is ill after reporting mild symptoms.