Andres Iniesta said Barcelona are "hurting" after Saturday's Clasico loss but have already turned their attention towards next week's Champions League quarter-final against Atletico Madrid.
Barca's run of 39 games without defeat in all competitions was ended by La Liga rivals Madrid, who came from behind to win 2-1 at Camp Nou.
Gerard Pique had given the home side the lead but Karim Benzema levelled things up just past the hour-mark before Cristiano Ronaldo hit the match-winner with five minutes left to play, despite Madrid going down to 10 men after Sergio Ramos saw red for a second bookable offence in the 83rd minute.
While the match did not go according to plan, Iniesta said the defending Spanish and European champions were already looking ahead to Tuesday's first-leg showdown against Atletico.
"We're hurting, but we're already thinking about the Champions League game," the Barca captain said.
"We have to analyse the things that we did not do well, but we have a new incentive, another competition to continue with.
"[The loss] does not affect us mentally for the game on Tuesday."
Barca hold a six-point advantage over second-placed Atletico in La Liga, while Madrid moved to within seven points of the league leaders in third.
"It hurts for everyone to lose, it hurts not to get the three points that would have kept the distance," Iniesta added.
"This is a league that is competitive until the end and there are options, although we are still in a privileged position, which would have been even clearer if we won.
"I do not think that we have to blame the physical aspect, in the end it was a set of things.
"At 1-0 we lacked more control, positioning, they've caught us in various counter attacks and these actions are very dangerous. It was more a matter of placement."