Real Madrid Starting XI: Casillas, Carvajal, Varane, Ramos, Coentrao, Pepe, Kroos, Isco, James, Ronaldo, Chicharito.
Atlético de Madrid Starting XI: Oblak, Juanfran, Miranda, Godín, Gamez, Tiago, Saul, Koke, Arda, Griezmann, Mandzukic.
Ancelotti decides to make some experiments and start Pepe in the midfield. That shows an evident lack of trust on Asier Illarramendi, who would be Luka Modric's most natural replacement. However, it's true that Pepe's experience and grit could be useful against a very physical Atlético de Madrid side. Furthermore, Pepe's aerial game could be crucial on set pieces, as Los Blancos will also need to focus on keeping a clean sheet.
All Real Madrid need to do is get a win, but that's something they haven't done throughout the entire season. The entire season could be at stake here, because nobody can tell whether Barcelona will drop points in the race for La Liga or not. Only time will tell.