Andres Iniesta has vowed that Barcelona will "play our hearts out" against Atletico Madrid after feeling they were "wronged" by the referee in Thursday's 1-1 draw at lowly Las Palmas.
Barca's lead at the top of LaLiga is now at five points and will be cut to two if they lose against Atleti at Camp Nou on Sunday.
It was a contentious equaliser for Las Palmas with Lucas Digne adjudged to have handled from the rebound after the ball hit the post following a tangle between Matias Aguirregaray and Sergi Roberto.
Veteran midfielder Iniesta acknowledged that Barca did not do enough to win despite that moment of controversy, but promised the team will be at their best against Atleti.
"We were wronged by 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."