Costel Pantilimon could return from an ankle problem, and Daryl Janmaat's groin injury will also be assessed.
Southampton goalkeeper Fraser Forster is expected to start after overcoming a minor thigh issue picked up in the EFL Cup final last Sunday.
Defender Martin Caceres awaits his Saints debut, while Virgil van Dijk is still sidelined with an ankle injury.
Steve Wilson: "This is the only Premier League game Southampton will play between 11 February and 19 March, so Claude Puel will be especially keen to see a points return from Vicarage Road. The Frenchman will also feel that he is due a slice of luck after Wembley.
"Walter Mazzarri's Watford look destined for another creditable mid-table finish, but that's unlikely to earn the Italian an invitation to stay a second season.
"Mazzarri is the eighth manager employed by the Pozzo family since their ownership of the club began in 2012, and has been wise enough not to invest too much time in learning English.
"A pat on the back and a pay-off is probably what Mazzarri expects in the summer. That is unless Watford should slump between now and May - in which case he can forget the pat on the back."
Twitter:@Wilsonfooty
Watford head coach Walter Mazzarri: "For sure Southampton played a great game [in the EFL Cup final] and maybe they are a bit disappointed because they could have gone at least to extra time, or even won the cup.
"We will see on Saturday if they will react or not, but nobody can know this.
"We got confirmation that they are a very well-organised team and a very strong team."
Southampton manager Claude Puel on his side's fixture schedule: "My biggest job now is to prepare the team for the difficulty of the calendar.
"We will play two games in a month after playing every three days since the beginning of the season. It's crazy - crazy for us and difficult."
Southampton were unlucky to lose at Wembley against Manchester United last weekend and now they can focus fully on the league.
But I don't fancy them to get anything at Vicarage Road. This is a tough game to call but I am going to go with the Hornets.
Prediction: 2-1
Lawro's full predictions v former England cricket captain David Gower.
Head-to-head
Watford
Southampton
SAM (Sports Analytics Machine) is a super-computer created by @ProfIanMcHale at the University of Salford that is used to predict the outcome of football matches.
Watford's January signing Mauro Zarate is out for the season after suffering a serious knee injury against West Ham.