Here, the PA news agency looks at what lies in wait for Jurgen Klopp's side...
History
This is only Genk's third appearance in the competition, their others coming in 2002-03 and 2011-12, after becoming Belgian champions for the fourth time in May.
They have yet to win a match in 14 attempts, the worst record of any of this season's teams. This is Genk's third game against Premier League opponents in this competition, having held eventual winners Chelsea 1-1 at home in 2011 after a lost 5-0 at Stamford Bridge.
However, including qualifiers Genk have lost just two of their 12 Champions League matches at home and are unbeaten in the last six, earning a goalless draw at the Luminus Arena last time out against Napoli.
Ones to watch
Tanzania's Mbwana Ally Samatta (pictured, above) scored five goals in his first six league matches this season but has not scored domestically since August 23.
His debut Champions League goal (not including qualifiers) came in the 6-2 defeat against Red Bull Salzburg in the opening game.
Midfielder Patrik Hrosovsky has the most European experience with 44 appearances, most of which came for Viktoria Plzen between 2011 and this year.
Lack of firepower
Genk's relatively inexperienced squad boast just three Champions League goals between them - Samatta, Jhon Lucemi and Hrosovsky (who scored for Viktoria Plzen against Real Madrid 12 months ago).
They have managed 44 career goals in all European competitions (Samatta 15 in 32 appearances, Paul Onuachu 10 in 31) from a total of 344 combined appearances.
By comparison, Mohamed Salah, Roberto Firmino and Sadio Mane have 49 between them in 95 Champions League games alone.
Coach
Felice Mazzu, son of Italian immigrants, is a former player-turned PE teacher who came through the ranks at Charleroi without playing a match - with his career being restricted to the lower leagues.
After a number of coaching jobs with several Belgian clubs he returned to Charleroi as head coach in 2013, where he secured their first European qualification for 21 years.
He only moved to Genk in June 2019, where he has won six of his 14 matches in charge.
