The Spain defender is selected at left-back as the Reds begin their campaign at Vicarage Road.
Elsewhere, summer signing Mohamed Salah is part of the three-man attack alongside Sadio Mane and Roberto Firmino.
Liverpool: Mignolet, Alexander-Arnold, Matip, Lovren, Moreno, Henderson, Can, Wijnaldum, Mane, Salah, Firmino.
Subs: Karius, Klavan, Gomez, Milner, Grujic, Solanke, Origi.