Koulibaly has been heavily linked with a move away from Napoli in recent years, but he is still at the Stadio Diego Armando Maradona.
This summer is no different and there is again speculation over his future at the club with suggestions that he could finally leave Napoli.
His agent has reportedly told Napoli that he will soon return with an offer for Koulibaly and Everton have been strongly linked with wanting to put him at Rafael Benitez’s disposal.
But according to Italian outlet Calciomecato.it, the Senegalese is wanted by his former Napoli coach Ancelotti at Real Madrid.
The Italian returned to the Bernabeu at the end of last season and is keen to sign a defender after watching Sergio Ramos and Raphael Varane leave.
He has requested Perez try and find a way to take Koulibaly to the Spanish capital this summer.
There have already been contacts between the two clubs to probe the feasibility of a potential deal.
Napoli want €60m for the defender, but Luciano Spalletti is keen that the Senegalese will stay at the club next season.