The Egyptian sat out the Premier League match at Old Trafford, which finished 1-1, because of an ankle problem.
He teams up with Sadio Mane and Roberto Firmino in the Liverpool attack in Genk, but Jurgen Klopp's side are missing key players elsewhere.
With Trent Alexander-Arnold ill, captain James Milner fills in at right-back, while Dejan Lovren plays alongside Virgil van Dijk in central defence as Joel Matip is sidelined.
There are also rare starts in midfield for Naby Keita and Alex Oxlade-Chamberlain.
Liverpool are currently on three points in Group E, one point behind leaders Napoli after two outings. Genk, the Belgian champions, are bottom of the section with just one point but held Napoli at home in their last European outing.