The Reds are back in continental action for the first time since April, playing in front of a full Anfield on a European night after 553 days away.
Their opponents, AC Milan, have never played at Anfield, while the two sides have not met since the Champions League final in 2007 – their only other meeting being in Istanbul two years prior.
Tonight brings first starts of the season for Gomez and Origi, while Nat Phillips makes the matchday squad for the first time in 2021/22.
Zlatan Ibrahimovic is missing for Milan, with Ante Rebic starting up front as Olivier Giroud returns to the bench.
Former Chelsea defender Fikayo Tomori starts at centre-back, with rumoured Liverpool target Franck Kessie taking up his position in midfield.
AC Milan: Maignan; Calabria, Kjaer, Tomori, Hernandez; Kessie, Bennacer; Saelemaekers, Diaz, Leao; Rebic
Substitutes: Tatarusanu, Jungdal, Ballo, Tonali, Giroud, Romagnoli, Kalulu, Florenzi, Maldini, Gabbia