Marco Silva, appointed Watford manager this summer, will be looking to get his Hornets reign off to a winning start but faces a tough task against a Reds side which finished fourth in the Premier League last season.
Silva has left his two big summer signings, strikers Richarlison and Andre Gray, on the bench but another new arrival, Nathaniel Chalobah, starts.
Liverpool boss Jurgen Klopp, meanwhile, has named his big close season signing, Mohamed Salah, in his starting XI.
Young full-back Trent Alexander-Arnold also starts as Nathaniel Clyne misses out due to injury.
The confirmed teams are available, in full, below…
Watford: Gomes, Janmaat, Britos, Kaboul, Holebas, Chalobah, Cleverley, Doucoure, Amrabat, Okaka, Pereyra.
Subs: Gray, Richarlison, Prodl, Femenia, Watson, Capoue, Pantilimon.
Liverpool: Mignolet, Alexander-Arnold, Matip, Lovren, Moreno, Can, Henderson, Wijnaldum, Salah, Firmino, Mane.
Subs: Karius, Milner, Gomez, Grujic, Klavan, Origi, Solanke.
Referee: Anthony Taylor (Cheshire)