Liverpool manager Jurgen Klopp has dropped left-back Andrew Robertson to the bench as he makes five changes to the team which beat Bournemouth 3-0 last weekend.
The Scotland international gets a rest while Joe Gomez moves to centre-back alongside Virgil van Dijk having started at right-back seven days ago and replaced the stricken Dejan Lovren against Red Bull Salzburg in midweek.
James Milner moves from midfield to full-back to replace Robertson at Anfield.
Trent Alexander-Arnold returns to the starting XI in the Premier League, while there are also roles for Sadio Mane and Xherdan Shaqiri.
For Watford, in new manager Nigel Pearson’s first game in charge, there are two changes.
Adrian Mariappa comes in for Adam Masina and Will Hughes replaces Roberto Pereyra in midfield.
CONFIRMED TEAMS
Liverpool: Alisson, Alexander-Arnold, Gomez, van Dijk, Milner, Henderson, Wijnaldum, Shaqiri, Firmino, Mane, Salah.
Subs: Keita, Adrian, Oxlade-Chamberlain, Lallana, Robertson, Origi, Williams.
Watford: Foster, Mariappa, Cathcart, Kabasele, Femenia, Doucoure, Capoue, Deulofeu, Hughes, Sarr, Deeney.
Subs: Gomes, Dawson, Chalobah, Gray, Quina, Success, Foulquier.
