Mourinho opted to include players like Jude Bellingham, Kylian Mbappé and Thibaut Courtois to face Racing at El Sardinero.
Real Madrid head to the game after beating Barcelona 2-1 in El Clásico last weekend.
Mourinho’s men currently sit in third position in the LaLiga table ahead of the Racing match.
Real Madrid’s squad against Racing Santander:
Goalkeepers: Courtois, Lunin, and Mestre.
Defenders: Militão, Huijsen, Trent, Konaté, Cucurella, Carreras, Rüdiger, and Dumfries.
Midfielders: Bellingham, Camavinga, Tchouameni, Arda Güler, Bernardo, and Thiago.
Forwards: Endrick, Mbappé, Espí, Brahim, and Yan Diomande.