Madrid travel to the Camp Nou for the first leg of the semi-final on the back of a 3-0 victory over Deportivo Alaves that left them eight points behind the pacesetters Barcelona after 22 of the 38 games in the Spanish top flight.
Karim Benzema, Vinicius Junior and Mariano Diaz were on target at the Santiago Bernabeu on 3 February against a side aspiring to gain one of the places that leads to next season's Champions League.
However, Barcelona are an entirely different proposition. The Catalans are seeking a fifth consecutive Copa del Rey title and will be keen to dispatch their rivals in the quest.
When they met at the Camp Nou in October in La Liga, Madrid's players slinked off the field after a 5-1 battering.
The next day, with Madrid in ninth place, head coach Julen Lopetegui was sacked after just three months in the job.
His replacement, Santiago Solari, appears to have steadied the ship with a blend of youth and experience.
Ballon d'Or winner, Luka Modric, continues to pull the strings from midfield and Solari has made 18-year-old Junior an important part of the first team squad.
"It was a complicated time for them psychologically when we last played," said Barcelona coach Ernesto Valverde before the first leg. "Now Madrid are in a different moment."
Both sides have a packed schedule to manage. In the next month, Barcelona play at Athletic Bilbao, Sevilla and Madrid. They also have two games against the French team Lyon in the Champions League.
Real Madrid take on Ajax in the same competition and go up against Atletico Madrid, Girona and Levante in La Liga.
"We are used to it," Solari said of the sequence of games. "This team has experience of this at this time of year. First, you have to reach this stage in all three competitions and then the aim is to keep all of them open."
The 42-year-old Argentine added: "We have already won the Club World Cup and we come into this period in good form and with energy. We face this run of games with absolute tranquility."