It's time to wake up for Real Madrid. Mourinho and his players haven't been performing well at all in this first half of the season, but it could all be forgotten if the team starts its engines and ends up winning the Copa del Rey and maybe the UEFA Champions League. In order to do that, los blancos will need to beat Valencia in this round and probably Barcelona in the semifinals. If it all goes as expected, Atlético Madrid will be waiting in the Copa del Rey Final.
But Mourinho might prefer to speak about first things first, as beating Valencia won't be easy. Soldado isn't playing his best football and they clearly lack some defense, but Valencia is still capable of scoring off set-pieces with Tino Costa crossing or shooting the ball. The Argentinian player will likely play as Valencia's defensive midfielder due to the absence of David Albelda. Fernando Gago just recovered from an injury and doesn't seem ready to stop Real Madrid's playmakers just yet.
Vicente Guaita will be the team's goalkeeper. He performed really well in the Santiago Bernabéu when Cristiano Ronaldo and his teammates couldn't score in last season's 0-0 match. Guaita saved a couple of big chances down the road and single-handedly prevented Real Madrid from winning that game, and he will try to do the same after losing the starting spot to Diego Alves in La Liga.
Sergio Ramos and Cristiano Ronaldo will return to the pitch for Real Madrid after missing the last game with a suspension due to five yellow cards seen. Both of them will try to rebound from the team's 0-0 draw against Osasuna in what was a very sub-par performance from their teammates. Coentrao will likely get the starting spot as the team's left back as well, since Marcelo doesn't seem fit to play 90 minutes yet. That way, Real Madrid's defensive line will look as usual, with Arbeloa on the right wing and two pure center backs in the middle.
Khedira and Xabi Alonso will play in the midfield if Mourinho doesn't feel like surprising anyone. A very different thing will be the team's offense. Özil seems to be a lock, but Di María's poor performances could cost him the starting spot in favor of Modric or Callejón. Higuaín played most of the game against Osasuna and has just recovered from an injury, so Benzema should be Mourinho's easy choice for the striker spot.
It will be very important (as always in these ties) to prevent Valencia from scoring away goals. To do that, the defenders and Casillas need to be ready to stop Soldado's chances but also be focused on Valencia's set-pieces. If they do that, the team should score some goals and win the game.