Manchester United have been tipped to sign Koulibaly from Napoli when the transfer window reopens at the end of the season.
Though the Red Devils’ defence is playing better under Ole Gunnar Solskjaer than it did under Jose Mourinho, there is still room for improvement.
Manchester United have Victor Lindelof, Eric Bailly, Chris Smalling, Marcos Rojo and Phil Jones on their books at the moment. Another centre-back, Axel Tuanzebe, is spending the season on loan with Championship outfit Aston Villa.
And the Evening Standard claim that United still want to sign Koulibaly at the end of the season.
It is said they tabled two bids recently but were turned down by Napoli on both.
There is hope, however, that Napoli will be more receptive to offers when the transfer window reopens at the end of the season.
The Evening Standard say Koulibaly is eager to move the Premier League and prove himself in England’s top flight.
But only time will tell if they are able to sign the Senegal international.
United do have four other players on their radar should their pursuit of Koulibaly fail to pay off.
Milan Skriniar has been backed to commit himself to Serie A giants Inter Milan.
But, despite that, United still have the 23-year-old on their list of potential defensive reinforcements.
Tottenham’s Toby Alderweireld was identified as a target during Jose Mourinho’s time in charge.
And he, too, is another player United are mulling over.
Harry Maguire of Leicester is also in their sights.
And as is Alessio Romagnoli, of AC Milan, who has starred amid a turbulent campaign under Gennaro Gattuso.
United are expected to cut Rojo loose at the end of the season.
The Argentine has won the FA Cup, EFL Cup and Europa League since joining from Sporting Lisbon in 2014.