Carvalho, Pepe, Ramos, Marcelo, Garay, Albiol, Arbeloa.
That's hardly enough for a club like Real, certainly if Garay is on the verge of going.
And then the quality, Marcelo is good as an offensive back. Carvalho has been a good surprise for me (put him in my Liga XI for Lemmi) BUT is getting older. Pepe (is he sure to prolong and stay?) and Ramos can be great but they are known for their short circuiting throughout the season. Albiol just isn't going to do it and Arbeloa is able but doesn't seem to do it under Mourinho.
First choice defense is below teams like Barcelona or United, and if you get a suspension or injury, Real is basically fucked at the back.