Real Madrid are preparing to fight Manchester United for defender Kalidou Koulibaly's signature.

United have eyed the Napoli defender since the summer, with former manager Jose Mourinho viewing him as the man to fix his leaky defence, and they made a world-record bid for him.

But, according to Italian outlet Il Mattino, they could face a serious rival for his signature.

Koulibaly has grown into one of the finest defenders on the continent over the last season and a half.

And that has led to Real eyeing him as a potential January addition as they look to recover from their shaky start to the season.

Napoli are believed to be willing to accept a bid of around £90million for the Senegalese star.