Both the Spain international and Los Blancos' recent signing from Tottenham Hostpur are included in Jose Mourinho's starting line-up as his side try and move up the Liga table
Elsewhere, the Portuguese coach has chosen to hand Luka Modric a starting berth in attacking midfield alongside Cristiano Ronaldo and Angel Di Maria, with Mesut Ozil restricted to a spot on the bench, while Karim Benzema starts upfront ahead of Gonzalo Higuain.
On-loan midfielder Michael Essien retains his place in defensive midfield after impressing against Manchester City during their Champions League clash midweek.
The Rayo Vallecano boss Paco Jemez has made a number of changes from the side that narrowly lost to Atletico Madrid on September 16.
Jemez hands a start to Andrija Delibasic, after the Montenegro international came on as a substitute and scored twice against Los Rojiblancos in their last Liga fixture. Delibasic will partner Leo Baptistao and Lass Bangoura in a three-pronged attack.
The Rayo coach has also decided to tinker with his formation, and has opted for a back four as opposed to his usual three-man defence, with Mikel Labaka slotting in alongside Jordi Amat at centre-back.
Alejandro Dominguez starts in midfield after also impressing as a substitute against Atletico, while first-choice goalkeeper Ruben also returns to the fold, having completed his suspension.
Rayo Vallecano (4-3-3): Ruben; Tito, Amat, Labaka, Casado; Carlos, Javi Fuego, Dominguez; Baptistao, Delibasic, Lass
Subs: Dani, Galvez, Gonzalez, Piti, Trashorras, Abu, Bille
Real Madrid (4-2-3-1): Casillas; Arbeloa, Pepe, Sergio Ramos, Marcelo; Xabi Alonso, Essien; Modric, Di Maria, Cristiano Ronaldo; Benzema
Subs: Adan, Varane, Albiol, Khedira, Ozil, Higuain