Napoli president Aurelio de Laurentiis confirmed that the Portuguese manager bid £95million for the 27-year-old centre-back. The report adds that the Italian wants £108million if he is to talk with interested parties for his defender.
Koulibaly is regarded as one of the best defenders in the world and has been impressive for Napoli in recent years. The report adds that Barcelona are also keeping tabs on the Senegal international.
United have struggled to keep clean sheets during the season and have conceded 32 goals from just 20 games.
The Red Devils also have a bit of an injury crisis when it comes to central defenders with Chris Smalling injured and the likes of Marcos Rojo and Phil Jones also picking up niggles throughout the campaign.
Koulibaly would be an excellent signing for the Red Devils who seem to be turning a corner under interim manager Ole Gunnar Solskjaer.
The Norwegian has helped the side to three wins from three games as we look to reach the top four at the end of the season.
It will be interesting to see how we deal with the current transfer window as some additions to the side could take us to the Champions League spots.