Watford could be without forward Cucho Hernandez, who hasn't trained since limping off during the first half of the defeat by Leeds.
Centre-back Nicolas Nkoulou is fit after a long-term hamstring injury.
Brentford defender Pontus Jansson is expected to play after missing last weekend's win over West Ham because of illness.
Josh Dasilva could return from a hamstring problem while Frank Onyeka's foot injury will be assessed.
LAWRO'S PREDICTION
Brentford are on a roll now, with four wins out of their past five games.
I don't know what is going to happen with Christian Eriksen because I am reading how all sorts of teams want to buy him in the summer, but he has arguably been the signing of the season and I'd love it if the Bees could find a way to keep him.