Barcelona coach Pep Guardiola believes Tuesday night's Champions League semi-final against Chelsea will define their season after losing El Clasico, and probably their La Liga crown, to Real Madrid.
Guardiola effectively ceded the Spanish title to bitter rivals Real after a 2-1 defeat at the Nou Camp on Saturday night left them seven points behind the Liga leaders with four games left to play.
Barca now host Chelsea looking to turn around their Champions League semi-final tie having lost 1-0 in the first leg at Stamford Bridge, determined to hang on to their European crown.
Guardiola told Sport: "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," Guardiola 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."
Looking ahead to Tuesday's test at the Nou Camp, Guardiola added: "Chelsea rested eight players (against Arsenal on Saturday), we did not."
One of the players that did not feature for the Blues was Didier Drogba, who scored the winner against Barca but is struggling with a knee injury and may not be fit for the return leg in Spain.
Asked if Drogba would recover in time, Chelsea manager Roberto Di Matteo told The Guardian: "At this moment of time, I don't know."
"We'll have to assess the players over the course of the weekend. He has an injury on his knee, which is why he did not play here, so it's whether the progression on this injury will be quick enough."
If Drogba doesn't make it, Chelsea will turn to Fernando Torres, who scored seven goals in ten games against Barca during his time at Atletico Madrid.