Real Madrid have Eder Militao and David Alaba as centre-backs now and they are the starting eleven players actually. But Ancelotti didn't prefer Alaba in the starting eleven yet. Nacho Fernandez filled his place.
These centre backs aren't enough to build Real Madrid defence. Nacho and Militao aren't strong defenders, it is clearly seen in the previous match against Levante. They were conceding 3 goals and almost be defeated by Levante in that match. If Ancelloti still dreams of the La Liga or UCL trophy, Real Madrid must plan to buy top centre backs. Then, Nacho and Militao are better to put as substitute defenders again.
I agree that Nacho Fernandez and Elder Militao cannot be relied on to defend Madrid's defence, because both of them have made mistakes several times.
I've been watching the game they both seem to be right they both don't deserve to be the starting eleven, so Madrid really have to bring in top defenders
if they really have the ambition to win the La Liga and Champions League trophies. If not then Madrid will find it difficult to face a big team that has
good strikers, against Levante alone they have conceded 3 goals. Especially against big teams like Barcelona and Atletico, I am very worried about
the current state of Madrid's defense. It's a very big hole left by Ramos and Varane, hopefully Madrid will bring in new defenders soon.