And United outdid Liverpool’s £75m move for Van Dijk by paying £80m for Maguire nearly two years ago, with the England international now the costliest defender on the planet.
The club’s defence has improved considerably of late, with Maguire, Victor Lindelof and Eric Bailly all stepping up.
But Koulibaly could be too good a signing to ignore at the end of the campaign, especially if Napoli decide to cash in.
Meanwhile, talkSPORT host Jim White has claimed Napili president Aurelio De Laurentiis has laughed off the prospect of Koulibaly leaving.
“There isn’t a window in the last two, three or four that we don’t see big mentions of the Napoli defender Kalidou Koulibaly,” White said.