Napoli have reportedly informed Chelsea that it will cost them £70m to sign Kalidou Koulibaly this summer.
Koulibaly, who has a contract with Napoli until the summer of 2021, represented Senegal at the 2018 World Cup, and is currently on holiday ahead of the 2018-19 campaign.
Chelsea have long been linked with a move for the 27-year-old, while Manchester United are also believed to have an interest in the powerful centre-back.
The Blues have already raided Napoli for their manager Maurizio Sarri and midfielder Jorginho this summer, and according to The Mirror, the Premier League outfit have been told that Koulibaly's price is no less than £80m.
The Senegal international has made over 150 appearances for Napoli since joining the Italian giants from Genk in 2014.