#2 Kalidou Koulibaly
The Senegalese international is presently among the best defenders in the world, and he has improved significantly during his time in the Serie A with Napoli.
Koulibaly is a quick, tall, a strong defender, comfortable with the ball at his feet, and has an excellent passing range. He has completed 791 passes this season, with an impressive accuracy of 90.3 percent. With 18 interceptions and 22 tackles completed in the league alone, he continues to excel as Napoli flourishes under Carlo Ancelotti.
The 27-year-old has played 135 games for the Naples outfit, scoring 8 times. He was a part of the Serie A Team of the Season in 2015-16 and 2016-17, and also earned himself a place in the CAF Team of the Year in 2016, after his fine defensive showings.
However, he recently signed a new contract with the Italian club, and Los Blancos need to dig deep into their pockets to sign the talented defender. He is also being linked with a move to Barcelona, which makes the situation more difficult for Real Madrid.