Barcelona boss, Ernesto Valverde, has admitted that Liverpool could beat his side and qualify for the final of the Champions League despite their three goals advantage.
The Spaniard noted that in football anything can happen, and that it would not be the first time if they lose today.
Barcelona travel to Liverpool for the second leg of their Champions League semi final with three goals advantage.
Last season, Roma shocked the football world when they upturned three goals deficit against Barcelona in Italy.
Evening Standard quoted the 55-year-old as saying that, "Experiences help a lot.
"They could beat us. In football, lots of things can happen. They are good, very good. They have lost only one match this season in the Premier League. They are extraordinary with set pieces. There is no relaxation.
"It's clear we had a bad result last year. We weren't good. Football gives you another opportunity. We played well in the first leg and we want to repeat. We are mentally prepared."
About their last defeat in Rome, he said, "I don't fear a comeback. The matches are there to be played. In the Barca-PSG tie, everyone thought PSG would go through if they scored, but Barca went and scored six.
"Nothing is written. You have to write it."