Agent Fulvio Marrucco would not confirm that Zola was heading for Stamford Bridge, where he is tipped to form part of Maurizio Sarri's backroom staff should the former Napoli coach replace Antonio Conte.
Maurizio Sarri's contractual situation with Napoli is expected to be sorted out by the end of June, according to Sky in Italy.
The former banker worked with Higuain at Napoli and is keen to get his hands on him again once he takes charge of Chelsea this summer.
The defender played in Senegal's 2-1 victory over Poland at the World Cup in Russian Federation and made the revelation when speaking to journalists after the game.
"I'm disappointed that he leaves like this, but we have now a big coach [Carlo Ancelotti]".
Mertens probably has a couple of good years left in him but having Eden Hazard on one wing and his Belgian teammate on the other could provide us with one of the most destructive attacks in the Premier League.
However, despite fresh interest from Chelsea this summer, Napoli president Aurelio De Laurentiis has identified Koulibaly as one of the players who is too important to lose. I hope he can win something with Chelsea. When a coach like this comes he needs time. They have to give him time because he will suit the football of Chelsea.
"At Napoli we enjoyed it very much as players and the supporters enjoyed it very much". I think Chelsea fans will enjoy the style of football he plays. It now remains to be seen if Sarri is able to convince the Chelsea board to sign Mertens and kick-start their transfer spending for the summer.
Koulibaly will be focussed on Senegal's next game on June 24 against Japan, who also won their opening game in Group H.