Watford attacker Sean Murray makes a return to the starting lineup after missing the midweek defeat to Brighton & Hove Albion.
Murray takes the place of Chris Iwelumo in the team, and there is also a start for 17-year-old Nathaniel Chalobah who displaces Jonathan Hogg.
For Bristol City there are two forced changes. Greg Cunningham and Cole Skuse are both out due to injuries picked up in the 2-1 win at Peterborough, with Joe Bryan and Albert Adomah named instead.
Watford: Almunia; Cassetti, Nosworthy, Neuton, Pudil; Chalobah, Abdi, Yeates; Murray, Forestieri, Vydra
Bristol City: Heaton, Foster, J.Wilson, Fontaine, Bryan; Adomah, Elliott, Pearson, Woolford, Taylor, Baldock