The French midfielder spent time on loan at Granada after joining The Hornets.
It looks like Watford could be selling a midfielder this summer, who has never played for the club – according to reports in France.
The report states that he is the subject of a €12 million (£10.4 million) from the Ligue 1 side.
Doucoure joined Watford in February for a fee reported by the Daily Mail to be in the region of £8 million.
Watford's Vicarage Road
However, he was immediately loaned out to another Pozzo family owned club in La Liga side Granada and has never played for Watford in a competitive match – however he did make his debut in some pre-season friendlies this summer.
A talented midfielder, Watford clearly see something in the talented Frenchman, but this would represent an immediate return on their investment if they did decide to sell him.
However, he is just 23-years-old, and Watford could have a future star on their hand and a potentially bigger future fee for his services should they decide to sell.
Doucoure played 15 La Liga games for Granada last season, helping them fight off relegation to the second tier.