#3 - Leonardo Bonucci:
Leonardo Bonucci had an impeccable 2016/2017 season with Juventus, guiding them to the UEFA Champions League final with an impressive defensive record, before eventually falling apart against Real Madrid. Rumors emerged that there had been a locker-room feud at halftime, which eventually led to the departures of the likes of Bonucci and Dani Alves.
The 30-year old has not enjoyed great success with his new club, AC Milan, so far, but his quality should not be put into question based on 2 months. He is head and shoulders above most defenders in the world, and features in the FIFPro team of the year, in central defence alongside Real Madrid captain Sergio Ramos.
Imagine what a duo these two monsters would form. Besides their defensive quality, both have world class ball-playing abilities and tend to operate as deep-lying playmakers, in many situations, in order to marginally improve their side's build-up play. After losing the precious services of Pepe, signing Bonucci would do Real Madrid no harm.
All in all, Bonucci has won 6 league titles, 6 Italian cups and 3 Italian Supercups. Leonardo has that winning mentality and would easily fit into the Real Madrid puzzle.