Watford have made one change to their side from their win over Arsenal. Deeney gets the nod to start over Andre Gray up front, with Richarlison and Roberto Pererya in support on the flanks.
Chelsea have made two changes from their draw during the week against Roma. Antonio Rudiger and Pedro come into the fold to replace Davide Zappacosta and Andreas Christensen in the line-up. Alvaro Morata leads the line for the second straight match since his return from injury.
Watford subs: Janmaat, Wague, Gray, Watson, Carrillo, Capoue, Karnezis.
WATFORD (3-4-3): Gomes. Mariappa, Kabasele, Britos; Femenia, Cleverley, Doucoure, Holebas; Pereyra, Deeney, Richarlison.
Chelsea subs: Caballero, Musonda, Zappacosta, Willian, Batshuayi, Christensen, Ampadu.
CHELSEA (3-4-3): Courtois; Rudiger, Luiz, Cahill; Azpilicueta, Fabregas, Bakayoko, Alonso; Pedro, Morata, Hazard.