Chelsea bid €58m for Napoli's Kalidou Koulibaly - Aurelio de Laurentiis

Napoli rejected a bid of around €58 million from Chelsea for defender Kalidou Koulibaly in the final days of the transfer window, president Aurelio de Laurentiis has claimed.

Koulibaly was one of Antonio Conte's top targets to bolster Chelsea's struggling defence this summer, but after a lengthy pursuit the Blues were frustrated by De Laurentiis' refusal to budge on his valuation of the player and instead re-signed David Luiz from Paris Saint-Germain on deadline day.

Conte pointedly complained that "it's very difficult to buy because if you ask a player of the medium level, they might ask for £55m" -- and De Laurentiis has said that he rejected an offer that would have made the 25-year-old the most expensive defender ever.

Speaking at the Leaders in Sport Business conference at Stamford Bridge, De Laurentiis said: "My friend Conte will say it is not true but Chelsea offered me, in the last few days of the window, €58m for Koulibaly. I explained to them that this year I could not sell him, but we will see next year."

Koulibaly signed a new contract with Napoli last month that commits him to the club until June 2021, but sources close to the player have told ESPN FC that he remains very open to the possibility of a transfer next summer; there have been reports that the new deal includes a release clause of more than £60m.

It has been reported that De Laurentiis' main objection to selling Koulibaly last summer was political -- Napoli supporters were already angered by the departure of top scorer Gonzalo Higuain to rivals Juventus for £75m, and the sale of two key players in the same window would have sparked further discontent.

Chelsea are likely to be in the market for defensive reinforcements again next summer despite the arrivals of Luiz and Marcos Alonso. Neither were on Conte's list of desired signings, while captain John Terry will be 36 in December and the recent form of Gary Cahill and Branislav Ivanovic has been disappointing.