Real boss Zinedine Zidane described the defeat as 'difficult and painful', so much so that club bigwig Perez took it upon himself to enter the home side's dressing room following the game.
The defeat for Real all but handed the title to Barca, with Ernesto Valverde's side now holding a nine-point advantage over Atletico Madrid in second and 14 points on Real in fourth, though 'Los Blancos' do have a game in hand due to their Club World Cup exploits.
"At this level it's all about fine margins, but we're not going to drive ourselves crazy. It's a difficult defeat for us, but we don't need to make any changes because we're never going to give up," Zidane told 'beINSports' following the loss.
According to Spanish publication 'Marca', the Real Madrid squad received an uninvited guest in their dressing room following the game, with Perez stopping by to encourage his side to keep their heads up despite the defeat.
The Real president's aim was to calm the situation and ease the tension that existed among the Real squad following the match, thus ensuring that the worst moment of the year for the club did not spiral into anything out of control.