Chelsea were keen on signing central defender Kalidou Koulibaly and even made a €50m (£42m, $56m) deal in securing his services. Napoli rejected the west London club's offer, the Serie A club owner Aurelio De Laurentiis has revealed.

The Senegalese international was strongly linked with a move to Stamford Bridge in the recently concluded summer transfer window as Antonio Conte was looking to bolster his back four. The Sun reported the defender was the Chelsea manager's top summer target. The Italian outfit were not willing to let their star defender leave, especially after allowing Gonzalo Higuain leave the club for Juventus in the same window.

Everton were also interested in Italian forward Manolo Gabbiadini. De Laurentiis revealed the 24-year-old was "unsellable" and thus his move to the Merseyside club did not take shape.

"Chelsea came in and offered €50m for Koulibaly, but he's going away for the African Cup of Nations, which pollutes the national Leagues and is another load of FIFA nonsense," De Laurentiis explained, as quoted by the Mirror.

"That's why we took [Lorenzo] Tonelli and [Nikola] Maksimovic to strengthen that area. As for Gabbiadini, he's unsellable, he is in tune with Maurizio Sarri and we believe our coach can get even more out of him."

Koulibaly was Chelsea's first choice player they were targeting in the centre-back position. Their failure to land the Napoli star saw the Blues look elsewhere in the transfer market. This saw Conte turn his attention towards David Luiz.

According to the Mirror, Luiz was not the first choice player wanted by the former Juventus manager. The Brazil international, who left Stamford Bridge for Paris Saint-Germain in 2014 returned to Chelsea on deadline day. He signed a three-year contract with the west London club.