The centre-back has previously represented Celtic in the competition, and having joined the Anfield side from Southampton in January, is offered his first chance to line-up under Jurgen Klopp on the continent.
Lovren switches in for Joel Matip alongside him in one of three changes to the starting XI.
The suspended Emre Can is replaced by captain Jordan Henderson at the base of midfield, while James Milner comes in for Alex Oxlade-Chamberlain.
Joe Gomez returns from a knee issue and is on the bench.
Liverpool starting XI: Karius, Alexander-Arnold, Lovren, Van Dijk, Robertson, Henderson, Milner, Wijnaldum, Salah, Mane, Firmino
Liverpool subs: Mignolet, Matip, Moreno, Gomez, Lallana, Oxlade-Chamberlain, Ings
Porto XI: Jose Sa; Ricardo, Reyes, Marcano, Alex Telles, Herrera, Sergio Oliveira, Otavio, Brahimi, Marega e Soares.
Porto subs: Casillas, Maxi Pereira, Osorio, Oliver, Corona, Waris e Goncalo Paciencia