Lille are reportedly planning an auction for their 20-year-old winger Eden Hazard.
With so many top European clubs interested in the Belgian, Lille have slapped a £40m valuation on the winger.
"Eden is certainly willing to stay at Lille at least until next summer," said the club's academy director Jean-Michel Vandamme.
"Chelsea have 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 us say he is not currently to go for less than £40m."
Hazard has scored 20 goals in 119 appearances for Lille.