Manchester United have reportedly 'shifted into high gear' for Napoli centre-back Kalidou Koulibaly.
The Red Devils are allegedly open to signing a new central defender during this summer's transfer window, and Koulibaly has been consistently linked with a switch to Old Trafford.
However, according to Le 10 Sport, United have stepped up their interest in the Senegal international as they look to tie up a move ahead of the 2020-21 campaign.
Napoli are thought to be open to selling Koulibaly this summer, although they are reportedly not prepared to lower their €110m (£96m) asking price despite the financial implications of the coronavirus outbreak.
The Italian club will be in a strong position when it comes to potential negotiations, meanwhile, as the defender has a contract with Gennaro Gattuso's side until June 2023.
United broke the transfer record for a centre-back when they signed England international Harry Maguire from Leicester City last summer.