Real's 3-1 aggregate win over Valencia in the quarter-finals has set up a mouth-watering clash with their great rivals and the holders Barcelona, who ousted Malaga in an absorbing 6-4 aggregate victory.
Leaders Barca already hold a seemingly unassailable 15-point advantage over Real in La Liga, and Jose Mourinho has written off his side's chances of retaining the title.
Mourinho has targeted the Cup and the Champions League instead and he has to negotiate what could be a pivotal week in the side's season and his Bernabeu future, at the beginning of March.
Real host Barca in the Cup first leg on Wednesday, and the return at the Nou Camp is scheduled for February 26-27, just before the league 'Clasico' at the Bernabeu on the weekend March 2-3.
Real play the Champions League last 16 second leg at Manchester United on March 5.
"A new storm of Clasicos: Three in a month," sports daily As said on Friday, recalling the four clashes between the sides in 18 days in April and May 2011.
After two-and-half years at the helm, Mourinho's future at Real is under the spotlight more than ever before, and he enters a critical five weeks with problems mounting at the club.
First-choice goalkeeper Iker Casillas fractured a bone in his left hand against Valencia during the week, and media have reported he will be out of action for six to eight weeks.
"Casillas is the captain, he is Madrid's emblem," Barca defender Gerard Pique said after their win in Malaga.
"Although [reserve keeper Antonio] Adan is a great keeper, the fact they are without their captain could affect the team."
Real still have time to dip into the transfer market before the end of January to find extra cover for Casillas should they deem it necessary.
The 2011 Cup winners also head into the first leg without winger Angel di Maria, and defenders Sergio Ramos and Fabio Coentrao who are all suspended, while Ramos's centre-back partner Pepe has yet to return after ankle surgery.
To add to their problems, Real have failed to put a lid on the constant media speculation over reported rifts within the dressing room.
Club president Florentino Perez took the unusual step of calling a news conference on Thursday to deny a newspaper story claiming a rift between Mourinho and club captains Casillas and Ramos.
The construction magnate branded sports daily Marca 'liars', and Ramos and Casillas, who are both reported to have had run ins with Mourinho this season, issued a statement backing both the president and their coach.
However, the daily has defended the piece saying it has text-message evidence supporting the story.
Get the best features, fun and footballing frolics straight to your inbox every week.
Thank you for signing up to Four Four Two. You will receive a verification email shortly.
There was a problem. Please refresh the page and try again.