Barcelona coach Pep Guardiola insists Tuesday night's Champions League return against Chelsea will now be the defining point of the season for the Catalan giants.
Guardiola effectively conceded the Primera Division title to bitter rivals Real Madrid after a 2-1 defeat in 'El Clasico' at the Nou Camp on Saturday night left them seven points in La Liga.
They now welcome Chelsea looking to turn around their semi-final tie having lost 1-0 in the first leg at Stamford Bridge on Wednesday, determined to hang on to their European crown having apparently lost their Spanish one.
Guardiola told www.sport.es: "We will see on Tuesday whether we will pass this test, but I think (the players) will lift themselves up and look at the manner of how things will go against Chelsea.
"What happens against Chelsea will mark the rest of our season. Although the guys have not had long to recover, they have had setbacks like this before and risen to the challenge."
Cristiano Ronaldo grabbed the winner for Real on Saturday night, seconds after Barca substitute Alexis Sanchez had cancelled out Sami Khedira's opener.
As was the case in the defeat to Chelsea, Barcelona failed to take a number of opportunities which came their way.
"I have seen the players' impotence," he admitted.
"We have opened up the field, we had opportunities...I think we had more chances than in other matches against Madrid. (But) these guys have four years of playing every competition possible and sometimes lack a little freshness. That can happen, especially bearing in mind the opposition.
"The effectiveness (in front of goal) has made the difference in these two games (against Real and Chelsea). But that's part of the game," Guardiola added.
Asked how he would spend his Sunday, Guardiola responded: "I will wake up relaxed, try to eat a bit and tomorrow I will talk with my colleagues to prepare for the next game, which is now the important thing. Chelsea rested eight players (against Arsenal on Saturday), we did not."
Guardiola felt Barca were more than a match for Real, adding: "I do not think we've been inferior to Madrid. Except the two goals, (Barcelona goalkeeper Victor) Valdes has had little work. We have taken the game to where we wanted. Now we are sad but from tomorrow we will recover to face the Chelsea game."
Barcelona midfielder Andres Iniesta also accepted defeat to Real in the title race, saying: "The league has escaped us. There are many points (to make up) and few games left.
"We have to pick ourselves up for Tuesday. (The defeat to Real) will take up today but tomorrow we have to switch on again, on Tuesday we cannot fail."
Meanwhile, Real assistant coach Aitor Karanka has called upon his side to overcome the odds again when they take on Bayern Munich at the Bernabeu on Wednesday needing to recover from a 2-1 first-leg deficit in their Champions League semi-final.
"Every match is different and important," Karanka told www.realmadrid.com.
"Nobody believed we would defeat Barcelona. We know the Bernabeu will be packed on Wednesday and we have to focus on turning the aggregate score around."
Karanka was delighted with the performances of Mesut Ozil and Ronaldo in particular.
"Ozil dispelled all doubts regarding the shape he's in. Cristiano Ronaldo is a great player and must continue performing like this. We are accustomed to seeing him give great performances," he said.
"He scored the goal that gave us the Copa del Rey title last year. He is the best player in the world."