Watford will be without Gerard Deulofeu for their opening Premier League fixture against Brighton.
The Spaniard, who joined from Barcelona this summer, has suffered from abdominal pain over the past few days.
It was believed Deulofeu could return in time for Saturday's clash, but manager Javi Gracia has confirmed his absence.
"Gerard started to train with the team last week, but he had a little problem," said Gracia.
"I think he will be ready in three, four or five days. Doucoure is fit and in a good condition to play. He's a player with great commitment, making a big effort every game."