Mohamed Salah will return to Liverpool for next week's Champions League clash with Belgium's Genk, while Trent Alexander Arnold and Joel Matip are missing.
Salah's place in the 19-man squad that traveled from John Lennon airport on Tuesday evening to Belgium, after missing his team's last game against Manchester United, which ended in a 1-1 draw.
However, Alexander Arnold did not travel with the team because of the illness, as Matip also missed, due to a knee injury.
The squad headed for Belgium included Alison Baker, Fabinho, Virgil van Dyck, Giorgio Venaldon, Diane Lovren, James Milner, Nabi Keita, Roberto Firmino, Sadio Mane, Salah, Joseph Gomez, Adrian, Jordan Henderson, Alex Oxlade Chamberlain, Adam Lalana, Ryan Brewemaster and Andrew Robertson and Andrew Robertson and Andrew Robertson and Andrew Robertson.