Deeney's return is the only change made by manager Marco Silva from the team that started against Swansea City last time out as Watford look to make it four wins from four Premier League away games this season.
Richarlison, who scored the winner against the Swans, will provide attacking support for Deeney, while Adrian Mariappa and Christian Kabasele once again make up the centre-back partnership despite Miguel Britos being available again after suspension.
West Brom, meanwhile, make three changes to the side which lost to Arsenal last weekend as Matt Phillips, Salomon Rondon and Chris Brunt all come into the starting lineup - the latter of whom is making his 350th appearance for the Baggies.
Jake Livermore, Allan Nyom and Hal Robson-Kanu drop out for the home side, who are looking for their first league win since August and their first victory in any competition in their last six outings.
Gareth Barry, meanwhile, starts again having become the Premier League's all-time leading appearance-maker during the loss to Arsenal last time out.
West Bromwich Albion: Foster; Dawson, Hegazi, Evans, Gibbs; Krychowiak, Barry, Phillips, Rodriguez, Brunt; Rondon
Subs: Myhill, Nyom, Robson-Kanu, Morrison, Livermore, McClean, Chadli
Watford: Gomes; Femenia, Mariappa, Kabasele, Holebas; Doucoure, Capoue; Carrillo, Cleverley, Richarlison; Deeney
Subs: Karnezis, Janmaat, Britos, Gray, Hughes, Watson, Pereyra
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