The league said it will take the case to Spanish authorities so they can pursue the necessary measures against the fan.
It was at the Santiago Bernabeu that Barca last tasted defeat in August as Real cruised to a 5-1 aggregate win in the Spanish Super Cup.
A two-week layoff since Real's last home game, though, has ensured groundsman Paul Burgess's best work will be on show for the big day.
Real Madrid midfielder Toni Kroos urged his side to push for the El Clasico win against arch-rivals FC Barcelona.
Often symbolised as pitting the pride of Catalonia against Spain's capital, the 'El Clasico' is a match laced with political tension.
Barcelona restored their lead at the top of La Liga to five points as the duo struck in the final 20 minutes to edge out 10-man Villarreal 2-0.
Toni Kroos and Achraf Hakimi rounded off the rout as Real leapfrogged cross city rivals Atletico Madrid into third.
The clash was expected to take place on December 20 as part of a full midweek round of fixtures before Spain's winter break.
Gerard Pique delivered Barcelona's match winner over Real Madrid on Saturday as El Clasico Miami lived up to the hype.