The 28-year-old, who has just 11 minutes under his belt from the bench this term, fills in for the suspended Wan-Bissaka following the full-back's red card in the 2-0 loss to Liverpool.
Ward's inclusion is the only change made by Roy Hodgson from that last outing, meaning that Christian Benteke will once again lead the line for Palace at Vicarage Road, while at the other end Wayne Hennessey retains his place in goal.
The visitors have lost just one of their last 16 meetings against Watford in all competitions.
Watford: Foster, Janmaat, Cathcart, Kabasele, Holebas, Hughes, Doucoure, Capoue, Gray, Deeney, Pereyra
Subs: Gomes, Prodl, Mariappa, Success, Masina, Sema, Femenia
Crystal Palace: Hennessey, Ward, Tomkins, Sakho, van Aanholt, Milivojevic, Schlupp, McArthur, Townsend, Zaha, Benteke
Subs: Riedewald, Kouyate, Guaita, Meyer, Sorloth, Kelly, Ayew
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