Doucoure has emerged as the one of the key players for the Hornets, with seven goals and two assists coming from 25 starts in the Premier League.
At a press conference, the 47-year-old told reporters: "I think he is playing well like the rest of the team.
"We got the victory in the last match because we played like a team and won as a team. I don't like to speak only about one player - of course all the players play at a high level because you need it if you want to win against Chelsea.
"I think [Doucoure] is in a big club at Watford. I hope he will be with us for many years to come. I am happy with their level and would like them to stay with us."
Doucoure's contract with Watford expires in 2020.