Victor Valdes admits Barcelona no longer have room for error in the race for the La Liga title after a frustrating 0-0 draw at Villarreal.
Real Madrid took advantage of their early kick-off on Saturday night, beating bottom of the league Real Zaragoza at the Santiago Bernabeu to put pressure on their great rivals at the top of the table.
And Barca were unable to respond on a disappointing night at El Madrigal, falling seven points behind Los Blancos after the stalemate against the Yellow Submarine.
With the gap to Jose Mourinho's side growing, Valdes admits Barca must hit the win-trail if they are to retain the domestic crown for a fourth consecutive season under Pep Guardiola.
"We have no more room for error. We have dropped two important points against Villarreal. We have to win all the points that remain," the Spanish international told Sport.
"And that's what you get. If we want to fight for the league, we can not fail anymore because there is a rival in front of us that is very strong."
The FIFA Club World Cup champions appear to be showing signs of tiredness, particularly on their travels away from the Nou Camp, but Valdes insists the December trip to Japan can't be used as an excuse for dropped points in recent weeks.
"Injuries can never be used as excuses. That would be small team that does that. There is enough [strength in depth] to deal with all of the games," added Valdes.
"[But] I have the feeling that we are tired. But we are facing opponents who are also playing a lot and nobody here ever said that this would be easy.
"I cannot say exactly what is happening, really. The important thing is that the team is working hard but we must continue giving our all - and more if necessary."
Guardiola's side will get their next chance to earn points against Valencia at the weekend, whilst the Catalan giants will also be keeping an eye on Madrid's clash with Getafe in the hope that the league-leaders drop points at the Coliseum Alfonso Pérez.