Manchester United should continue their interest in Napoli defender Kalidou Koulibaly in order to secure a deal for him to move to Old Trafford.

José Mourinho's team has had some real defensive worries this season with Chris Smalling and Victor Lindelof operating as a centre-back pairing for the majority of the season after Eric Bailly appeared to have fallen out of favour with the manager.

According to Argentinian broadcaster Tyc, via Team Talk, did United have a bid of around £77m for the Senegal international rejected recently and will they have to pay close to a staggering £90m if they want to sign him in the upcoming January transfer window. The deal would make the 27-year-old the most expensive signing for a defender in the world should it go through.

But it is expected that the Italian outfit would want to keep hold of Koulibaly for as long as possible with Carlo Ancelotti rebuilding the club after the departure of Maurizio Sarri. Napoli have had a good start to their season and have proved to be the only worthy challengers for Juventus in the Serie A, while they are also finely poised to qualify for the knockout stages of the Champions League after beating Liverpool and keeping PSG to successive draws.

Koulibaly's contribution to these good results has been massive and is it now surprise why a club like United are planning to break the bank for him. The former KRC Genk player would be a huge addition to the current Red Devils squad and will make an immediate impact that would drastically improve the club's defensive structure.

Mourinho wanted to sign a centre-half in the summer but didn't receive the backing from vice-chairman Ed Woodward for that to happen, but after the poor performances this season, the manager is expected to receive the necessary cash in order to rectify those defensive problems.

Koulibaly would bring the needed stability to the back-four while his physical presence would be a perfect fit for the Premier League. His aggressiveness would also be a major bonus for United after the current set of defenders have been often been bullied by opposition attackers.