Manchester United and Jose Mourinho's split stemmed from the club's unwillingness to buy a central defender in the summer.

After guiding the Red Devils to second in the Premier League, the Portuguese was desperate to land a world-class name to bolster his defence.

Sadly, Ed Woodward didn't agree and 19-year-old right-back Diogo Dalot was the only defensive reinforcement brought in.

Mourinho's main targets in the summer were Premier League duo Toby Alderweireld and Harry Maguire, but the club just wouldn't back either pursuit.

All season long, the Red Devils have looked shaky at the back, with Victor Lindelof the only central defender starting to show very promising signs of late.

As such, United have a four-man list of central defenders that they are targeting, according to ESPN.

Alderweireld is no longer on there, with Milan Skriniar, Alessio Romangoli, Maguire and Kalidou Koulibaly the quartet being targeted.

The latter is the name the club are dreaming of and United are aware that the Napoli man will cost around €100m.

But how does the 27-year-old Senegal international feel about United's interest? Well, inside sources have confirmed to ESPN that he is open to the switch.

The report details that the Red Devils are aware that they may have to wait until the summer to get Koulibaly, who recently signed a new deal in Naples.

United certainly have the financial power to match Koulibaly's valuation by the Serie A side, which would probably see the Senegalese eclipse Virgil van Dijk as the world's most expensive defender.

However, the success Liverpool have had since splashing £75m on the Dutchman is evidence enough that United should make the move.

Koulibaly is recognised by most football fans as one of the most complete centre-backs in world football, a man arguably capable of solving United's defensive woes overnight.

Him and Lindelof could be the perfect partnership to the Red Devils' new era.