Manchester United have tabled a bid for Napoli defender Kalidou Koulibaly.
Gazzetta dello Sport says Napoli have rejected United's opening offer for Koulibaly.
The English giants offered €30m for the 30-year-old Senegalese, which was immediately turned down by the Neapolitans.
The Italian club is demanding at least €50m for their defender.
Koulibaly moved to Napoli from Genk in 2014 for almost €8m. Last season he made 37 appearances in all competitions for Napoli.
