However, Lille's vice general director Frederic Pacquet has warned the Blues not to approach star man behind their backs, and intends to keep hold of the 20-year-old Belgium international.
Pacquet, speaking to French sports paper L'Equipe said: "If Chelsea directly contacted Eden, we would take offence at it.
"That is not the right custom.
"No one is up for sale - that is very clear. We want to keep as many players as possible."