Manchester United have been told that they will have to pay a world record transfer fee to sign one of their main defensive targets just some weeks before the start of the January transfer window.
The Red Devils are one of two clubs keen to sign Napoli defender Kalidou Koulibaly.
The Senegalese international centre back has grown to be one of the best defenders in world football since he joined Napoli from Belgian champions Genk.
Chelsea is the other Premier League club interested in him though Manchester United are favourites to secure his transfer from Napoli.
Kalidou Koulibaly played under Maurizio Sarri at Napoli before the Italian tactician left the club for Chelsea this summer.
Maurizio Sarri became the Blues boss earlier this year after putting pen to paper on a three-year contract as the replacement for compatriot Antonio Conte who was sacked after an underwhelming outing in the last campaign.
According to the Daily Mirror via teamtalk, Manchester United and Chelsea will have to pay at least £90m to sign the 27-year-old.
It would be a world record fee for a defender eclipsing the £75m that Liverpool paid to sign Dutch defender Virgil Van Dijk from fellow Premier League side Southampton in January.
The Red Devils reportedly had a £77m bid rejected for Kalidou Koulibaly.