Koulibaly has told Napoli he wants to leave if the club receive a good offer. The defender spoke directly with president Aurelio de Laurentiis recently about his plans.
Le 10 Sport says the Senegal international's dream is to play in England - and he is attracted by the prospect of working with Ole Gunnar solskajer at United.
In Naples, it's been suggested United will tempt Koulibaly away with an offer to make him the highest paid player at the club.
But they will still have to negotiate terms with De Laurentiis, who will insist near €100m to part with his star centre-half.