Chelsea are all set to launch a fresh bid for Napoli defender Kalidou Koulibaly.

The Senegal international is Antonio Conte’s top target but the Blues have already had a £42m offer knocked back by the Serie A giants.

According to Calciomercato.it, Conte has not been put off by Napoli’s stubborn stance and is prepared to launch a second bid worth up to £48m in the next few hours.

However, the Italian website claim Napoli president Aurelio De Laurentiis will battle to keep Koulibaly on the condition he can leave next summer.

Conte is keen to strengthen his central defensive options before the window slams shut with just veteran skipper John Terry, Gary Cahill, and Kurt Zouma in his squad.

Chelsea opened their Premier League campaign with a win over West Ham and the Italian boss is keeping one eye on the transfer market.

He said: “It’s important to have contact every day with the club.                              

“The market is very crazy, the club knows my ideas and it’s important to find the right solution to improve this team, not to buy for the sake of it.

“We are waiting for the right solution but I’m very happy to have these players because every day they show me a great attitude.

“There are two weeks and we’ll pay attention if we find the right solution that’s fine.”

The 25-year-old Napoli defender was impressive for the Serie A giants throughout last season, making 33 appearances as his team finished runners-up to Juventus.

And his exciting form apparently caught the eye of new Chelsea boss, Antonio Conte, with the Italian making the Senegal international his top priority target this summer as he is keen to overhaul his new squad following their unexpected 10th place Premier league finish last term.

Conte needs a new defender with just Kurt Zouma, Gary Cahill and John Terry his only first-team options at the back.

Skipper Terry, 35, is expected to play a reduced role this season, while Zouma is recovering from a knee injury.

Right-back Branislav Ivanovic could cover the central positions until a permanent arrival is sorted.