Watford remain without captain Troy Deeney for the visit of Sheffield United, but boss Quique Sanchez Flores is positive he will be back soon.
The forward underwent knee surgery in August after playing in the Hornets' first two matches of the season.
Sheffield United captain Billy Sharp will return to contention following suspension.
Sharp is expected to be included in Chris Wilder's squad after sitting out last week's home defeat to Liverpool due to a one-game ban.
Fellow striker David McGoldrick remains sidelined with a groin problem, which has kept him out for three matches.
Watford provisional squad: Foster, Dawson, Mariappa, Kiko, Holebas, Foulquier, Cleverley, Doucoure, Hughes, Capoue, Deulofeu, Gomes, Janmaat, Cathcart, Kabasele, Chalobah, Sarr, Pereyra, Gray, Welbeck.
Sheffield United provisional squad: Henderson, Baldock, Stevens, Fleck, O'Connell, Basham, Lundstram, McBurnie, Robinson, Egan, Norwood, Mousset, Sharp, Freeman, Jagielka, Osborn, Moore, Besic.