Manchester United are reportedly interested in signing Napoli defender Kalidou Koulibaly this January, with Ole Gunnar Solskjaer said to be keen on another defensive addition.
United signed Harry Maguire from Leicester City and Aaron Wan-Bissaka from Crystal Palace in the summer, but reportedly retain an interest in the Senegal international.
According to the Daily Star, Koulibaly's relationship with Napoli president Aurelio De Laurentiis has soured recently and the club would be willing to sell at the right price.
The report adds that Napoli want close to £100m if they are to part with the man named Serie A defender of the year last season.
Manchester City, Tottenham Hotspur and Chelsea are also said to have shown interest in the former Genk man, but United are reportedly at the head of the queue.
The Red Devils were thought to be considering potential replacements for Maguire amid fears that the centre-back could miss a prolonged spell through a hip injury, but Solskjaer has quelled those concerns by revealing that the England international could face Norwich City on Saturday.