MANCHESTER CITY have made an opening offer for Napoli centre-back Kalidou Koulibaly, according to reports.

The Etihad outfit have already secured the £41million signing of Bournemouth defender Nathan Ake this summer as they attempt to close the 18-point gap to Liverpool at the top of the Premier League.

City are hoping to tempt the Italian side into selling Koulibaly with an opening bid of £57million plus bonuses, but it is thought Napoli will hold out for at least £63million up front.

Koulibaly, 29, has been a long-standing target for a number of top clubs, including City and rivals Manchester United.

United, however, have yet to make a formal offer for the Senegalese international.

Napoli are hoping the sale of Koulibaly can help recoup some of the club record £74million spent on the signing of Lille striker Victor Osimhen.