The 20-year-old was one of the most sought-after prospects in football over the summer, with Arsenal, Liverpool and Manchester City all linked with a move for him.
Hazard remained at the Stade Metropole this summer, but it seems unlikely that he will stay beyond next year's transfer window.
Lille academy director Jean-Michel Vandamme revealed that the club is expecting to cash in on the sought-after Belgian with most of Europe's top clubs already keeping tabs on him.
He was quote as saying on the Daily Mail: "Eden is certainly willing to stay at Lille at least until next summer,
"Chelsea has been following him the closest. The Spaniards have not manifested themselves yet, but I think they are playing it smart and will call when they know they have to - I'm talking about Real Madrid, but also about Barcelona.
"The buyer will have to come up with a lot of money - let's say he is not currently to go for less than £40million."
Patrick Vieira, who is currently a development director at Manchester City, was spotted in the Stade Metropole watching Hazard play against Inter Milan in the Champions League mid-week.
Inter captain Javier Zanetti was the one who had the closest look, having had first-hand experience of Hazard's capabilities in the flanks.
He said: "Eden is a player that I like. And I know that Inter are watching him. The club is very interested in this player. In my opinion, he has the level to play for us."