Injuries to Pepe and Raphael Varane has sent alarm bells ringing around Real Madrid ahead of the busy fixture run-in, although the answer could lie at La Fabrica.
Only Sergio Ramos and Nacho Fernandez are fit to play at centre-back and the former is on the verge of suspension in the Champions League, as is the latter in LaLiga.
Therefore Castilla boss Santiago Solari has endorsed the options at hand in the club reserve side, starting with vice-captain Mario Hermoso.
Spending last season on loan at Real Valladolid, the 21-year-old is a left-footed centre-back with strong aerial and ball-playing skills, and is an undisputed starter in Segunda B.
Also available is Austrian Under-21 international Philipp Lienhart.
Another who has spent time on loan away from the Spanish capital, at Rapid Vienna in 2013/14, the defender has previously been picked by Rafa Benitez for a spot on the Real bench and made his first-team debut in the December 2015 Copa del Rey win over Cadiz.
If Zidane wants to opt for a more raw talent, teenager Javi Sanchez could be selected given his excellent showings when covering for Lienhart.
Sanchez also boasts a solid goalscoring record, making him a good foil for Ramos if the club captain needs a rest, with Alex Salto another option. However, the Alicante-native has only just returned from injury.
