Swansea City's Jack Cork (ankle) has been ruled out, with Leon Britton and Jay Fulton in contention to replace the midfielder.
Striker Fernando Llorente has trained and is available for selection.
Watford defenders Younes Kaboul (thigh) and Sebastian Prodl (rib) and midfielder Valon Behrami (hamstring) are all doubtful for this weekend.
Miguel Britos is suspended, but Troy Deeney is expected to start after only being used as a substitute last week.
Did you know?
This will be the fourth time Watford and Swansea City have faced each other in the Premier League, with each team's record being W1 D1 L1.
A PL-high 24% of Swansea City's total attempted shots this season have been headers, while they have also attempted the most headed shots (84).
The Hornets have scored the highest proportion of goals in the opening 15 minutes of Premier League matches this season – 25% (9/36).
Troy Deeney has scored six goals in his last eight Premier League starts for Watford, including in his last four appearances at Vicarage Road.
What the managers say
Walter Mazzarri: "No [we are not safe] - not until the numbers say we are safe. I tell my players to fight every game like it is a cup final."
See: Mazzarri on Swansea
Paul Clement: "For us it's about focusing on the task in hand and that is our game at Watford. We can't focus on anyone else or anything else."
See: Cork injury update
