According to Sky Sport Italia, Sportitalia and more, all the details are essentially in place for the clubs to move very quickly indeed.
As a sign of how advanced the situation is, the defender was meant to arrive at Napoli’s training camp in Dimaro this evening, but he remained on vacation in Milan.
Reports all point towards the transfer fee being €40m including add-ons, with Sky Sport Italia specifying €38m plus €2m bonuses.
The details on personal terms differ slightly depending on the various sources.
Sky Sport Italia suggest a five-year contract worth €10m per season, whereas Sportitalia point to three years and an option for a fourth, worth €8m plus €1m in add-ons per season.
Whatever the details, everyone in Italy is entirely confident now that Koulibaly will join Chelsea over the next 24 hours.
His contract with Napoli is due to expire in June 2023 and he rejected an initial proposal to renew with his wages halved, then did not give a response to the second offer at €6m per season.