The Catalans were humiliated by Bayern Munich 4-0 in the first-leg of their Champions League semifinal.
Messi said: "It's difficult to fight back, but we'll try to score the goals we need at the Camp Nou. We have to pick ourselves up, finish off La Liga and try to comeback against Bayern."
Xavi remarked: "The result is a bit excessive, but they were the better side. We have to congratulate them because they were superior, they took advantage of their assets. We will try to fight back, because we're Barça and we'll keep on fighting until the end."