Manchester United have seen a bid for Napoli centre-back Kalidou Koulibaly rejected by the Italian club, according to a report.

Speculation over the Senegalese defender's future has cooled in recent months, with Man United and Manchester City failing to prise him away from Naples last summer.

However, Napoli are understood to be open to bids for Koulibaly this time around, and the Red Devils have been tipped to reignite their interest, despite making progress in their pursuit of Raphael Varane.

According to Gazzetta dello Sport, United approached Napoli president Aurelio De Laurentiis with an offer of €30m (£25.9m), but the bid was swiftly rejected.

The report claims that it would likely take an offer closer to €50m (£43.2m) to strike a deal for Koulibaly, whose deal in Naples now has under two years left to run.

Koulibaly featured on 37 occasions in all competitions for Napoli last term, and he was previously linked with a move to Everton while Carlo Ancelotti was in control of the reins.