According to the Italian football transfer expert, the Blues have agreed to personal terms with the Senegalese international, who is expected to sign a five-year deal worth €10 million per year with them.
Romano wrote on his Twitter account:
"Kalidou Koulibaly to Chelsea, here we go! Full agreement in place for €40m fee add-ons completed, bid accepted. Napoli are checking the documents then it will be official. Koulibaly will sign long-term deal for €10m net salary per season. First centre back, signed."