According to Corriere dello Sport, via The Hard Tackle, Koulibaly wants to leave Napoli this summer.
His contract with Napoli expires next summer, but he is not looking to sign a new deal with the Serie A side.
However, Chelsea want to take Koulibaly to Stamford Bridge.
The Blues will have to battle Juventus, who are also keeping a close eye on Koulibaly’s situation and are offering him the chance to stay in Italy.
But the 31-year-old wants to leave Italy this summer and experience a new league.
That will be music to the ears of Chelsea manager, Thomas Tuchel, who has the player on his wishlist to replace Antonio Rudiger, who has since joined Real Madrid this summer on a free transfer.