This clash matters far beyond the ninety minutes between Barcelona and Real Madrid. The refereeing decisions will be scrutinised by millions around the world, and so all eyes turn to Juan Martínez Munuera, handed the task of officiating El Clásico amid an atmosphere thick with sporting and refereeing controversy in La Liga.
The Technical Committee of Referees of the Spanish Football Federation confirmed Munuera for the eagerly awaited meeting at the Spotify Camp Nou on Sunday evening, part of the tenth round of La Liga. Javier Iglesias Villanueva takes charge of the Video Assistant Referee (VAR) role.
Given the global interest in the fixture, Munuera spoke to the "DAZN" network about his feelings towards the assignment, how he handles the pressures surrounding the clash, and the particular routine he keeps before matches.
The Spanish referee said: "When one receives such an assignment, one always feels grateful for the committee's trust, while being aware of the responsibility one bears, as is always the case. But we all know that this match enjoys great global interest, and so we approach it calmly, exactly as the teams do. During the week, we focus on the European competitions, then we turn our attention to the weekend matches."
On criticism and the endless talk around refereeing, Munuera said he prefers to stay away from the media noise and focus on his work, picking carefully what he reads or listens to.
He explained: "In general, I have for a long time tended to isolate myself from what goes on around me, and to be very selective about what I read or listen to. The people around me know they need to filter out a lot of things, because we have to live in peace, and preserve the confidence we are used to."
Music, it turns out, has become a fixture of the build-up. The Clásico referee revealed details of the routine he follows with his team before kick-off, alongside reviewing the points raised in the morning meeting.
Munuera said: "We have developed our routine, as we play music at all matches. And just before going out onto the pitch, we confirm the points we spoke about earlier during the morning meeting, then we play a song that is very special to us, in appreciation of what our families have given us."
His words land before one of the most closely followed matches of the season. The contest between Barcelona and Real Madrid piles extra pressure on the officials, who must manage it all under the gaze of fans and media alike.