Watford captain Troy Deeney will miss the visit of West Ham after he was ruled out through injury.
Deeney underwent a knee operation on Thursday and is expected to be sidelined for several weeks.
West Ham are set to be boosted by the return of captain Mark Noble who has missed the opening two matches with a calf problem.
Provisional Watford squad: Foster, Femenia, Dawson, Cathcart, Holebas, Hughes, Doucoure, Capoue, Sema, Gray, Pereyra, Deulofeu, Gomes, Janmaat, Cathcart, Cleverley, Okaka, Welbeck, Chalobah, Quina, Masina, Sarr.
Provisional West Ham squad: Fabianski, Fredericks, Balbuena, Diop, Masuaku, Rice, Fornals, Wilshere, Noble, Lanzini, Anderson, Haller, Anderson Roberto, Zabaleta, Ogbonna, Cresswell, Sanchez, Snodgrass, Yarmolenko, Antonio, Hernandez, Ajeti.