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.
Liverpool and Paris Saint-Germain are also believed to be interested in signing the 28-year-old, who has only made 15 league appearances this season due to injury.
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.
