Right-back: Keiran Trippier (Atletico Madrid)
Just in time for an important derby, Kieran Trippier returns to the Atletico Madrid team following a betting ban that had ruled him out since the turn of the year.
Nevertheless, the English full-back has had a good season, making five assists in 14 La Liga games while putting in excellent shifts defensively too. Diego Simeone will hope for Trippier to replicate some of that form against Real Madrid.
Centre-back: Raphael Varane (Real Madrid)
Raphael Varane's future at Real Madrid has come under the scanner once again. But the 27-year-old hasn't let those exit rumours distract him from giving his best on the field.
With a defence that's reeling from the absence of captain Sergio Ramos, Varane has truly stepped up to the plate. However, he will have the onus of shutting out Atletico Madrid's Luis Suarez in the game.
Centre-back: Stefan Savic (Atletico Madrid)
With Diego Simeone adopting a three-man backline this season, Atletico Madrid's defence has returned to being one of Europe's meanest. One player to have truly impressed in this set-up is Stefan Savic.
The Montenegrin star is back in form again this season. He has averaged over three clearances, 2.5 aerial duels and a pass completion rate of over 85% per game.
Left-back: Ferland Mendy (Real Madrid)
Ferland Mendy's meteoric rise at Real Madrid is well documented, as the French fireball has usurped the legendary Marcelo to establish himself in Zinedine Zidane's set-up.
Mendy has continued in the same vein this season, even though the manager will expect more from him from an attacking standpoint too.