Midfielder Maxime Lestienne and unused substitute Eden Shamir are among the new cases to hit the Belgian outfit.
Teenage striker Abdoul Fessal Tapsoba has also tested positive for Covid-19 but was not among the Standard squad which suffered a 2-0 Europa League defeat to Steven Gerrard's team on Thursday.
Tapsoba had already been told to isolate after team-mates Michel-Ange Balikwisha, Nicolas Raskin and Moussa Sissako were found to have contracted the virus on the eve of the Gers clash.
The newly-affected trio will now sit out Sunday's Jupiler Pro League clash with Sint-Truidense VV and as well as next week's Europa League trip to Benfica.
Liege said in a statement: "Early Friday afternoon, the entire Reds delegation underwent a Covid-19 test.
"The results received this Saturday at the beginning of the afternoon indicate that Maxime, Eden and Abdoul are positive.”