Midfielder Andres Iniesta insists Barcelona will hit back immediately and put the title to bed with victory over Atletico Madrid on Sunday.
The Catalans saw their lead at the top of the La Liga table reduced to just five points after they were held to a 1-1 draw by Las Palmas on Thursday.
Atletico beat Leganes 4-0 on Wednesday to make it six consecutive top-flight victories, and eight in nine games, as the capital outfit refuse to go away in the battle for league honours.
Barca sit at the top of the standings on 66 points but have drawn three of their past five games and defeat this weekend would throw the title race wide open.
Iniesta is determined that will not happen and, with a feeling of injustice after their midweek efforts, has made it clear there will be a response from his team-mates at the Nou Camp.
“We were wronged by the referee but we were also not good enough,” he said. “We lacked motivation to make it 2-0 or win the game.
“On Sunday, we will play our hearts out to increase the difference in points between us and Atleti.”
Barcelona are yet to lose in the league this campaign, with 20 wins and six draws, and have conceded just six goals at home.
It is clearly going to be a tough task for Diego Simeone’s side and much will depend on the form of France striker Antoine Griezmann, who netted all four goals in midweek.
He tops Los Rojiblancos’ goalscoring charts this season, with 15, but netting just once at the imposing stadium will be tough given the Barca’s record on their own patch.
Atleti have only scored 45 in the league all season and Angel Correa, with six, is the next highest scorer after Griezmann.