Birmingham City have made two changes to the side that beat Charlton Athletic at the weekend for tonight's trip to Vicarage Road.
Brian Howard and Albert Rusnak both come into the side, while Lee Novak and Olly Lee both drop to the bench.
The hosts, who drew with league leaders Leicester City on Saturday, have also made two changes for tonight's match.
Ikechi Anya misses out with a calf strain, with Alexander Merkel taking his place, while Daniel Pudil comes in for Sean Murray.
Watford: Almunia, Faraoni, Merkel, Ekstrand, Cassetti, Angella, Pudil, Battocchio, Forestieri, Deeney, Tozser
Birmingham: Randolph, Caddis, Robinson, Adeyemi, Martin, Packwood, Burke, Huws, Howard, Macheda, Rusnak