United are expected to seek defensive reinforcements this summer.
They have faced a nightmare at the back all season after ex-boss Jose Mourinho was refused the money to bring in new blood last summer.
The Portuguese was chashing a world-class centre-back, and names linked with a move to Old Trafford included Toby Alderweireld, Jerome Boateng and Diego Godin.
But with a new permanent manager in charge come the end of the season, United's transfer chief Ed Woodward is prepared to pump big money into the transfer market this time around.
Liverpool currently hold the record fee for a defender after they handed Southampton £75m for Virgil van Dijk last January.
But that record could be blown out of the water this summer.
United are understood to have been keeping tabs on Napoli centre-half Kalidou Koulibaly over the past few months.
And the Serie A side have slapped a whopping £150m price tag on the Senegalese's head, according to the Daily Express.
Chelsea were chasing the 27-year-old last summer.
But after another impressive season at the San Paolo Stadium, the Azzurri have more than doubled his price tag.
Barcelona and Real Madrid are also believed to have Koulibaly in mind for their transfer plans this summer.
But unlike United, they appear to have been put off by Napoli's sky high valuation.
Starsport exclusively revealed earlier this week that United caretaker boss Ole Gunnar Solskjaer had given the green light to splash £65m on Leicester man Harry Maguire.
The Norwegian is yet to officially be given the Old Trafford hot seat permanently.
But Solskjaer is keen to get the player in so he can potentially remodel his defence around the World Cup hero should he be given the job.