Real Sociedad have an important aim this season: they want to be in the Champions League places. At the moment they are in fourth, tied with Valencia on 62 points. Atleti have third entirely sewn up. This game means a great deal to Real Sociedad as a consequence.
They are not an in-form team, however. Valencia has been allowed to close the gap on the Champions League places because in their last five games Real Sociedad only have two wins.
Real Madrid have won their last 7 games against Real Sociedad. In his last 4 games against them, Ronaldo has scored an eye-watering 6 times.
Jose Mourinho has called up 20 players.
Goalkeepers: Adán, Diego López and Jesús.
Defenders: Pepe, Carvalho, Marcelo, Arbeloa, Albiol and Nacho.
Midfielders: Khedira, Kaká, Özil, Essien, Modric, Callejón and Di María.
Forwards: Cristiano Ronaldo, Benzema, Higuaín and Morata.
Iker Casillas, the most obvious absence, has back discomfort. Sergio Ramos, Xabi Alonso and Fabio Coentrao have also been left at home having picked up knocks against Atleti on Friday. Nacho has earned himself another call-up.
Carlos Vela is suspended for Real Sociedad, and they waiting on Asier Illarramendi's injury to see if he can play.