Barcelona coach Xavi was delighted with their Copa del Rey win at Unionistas.
Barca won 3-1 to reach the quarterfinals as Ferran Torres, Jules Kounde and Alejandro Balde struck.
Xavi later said: "I think that at times we have played very well and at times we have to play better. Sometimes I despair because we don't do the right thing. We have had errors of lack of aggressiveness.
"But we have come back. We are under construction, we have to generate more, we have to understand the situations better... There are very young players, but we gain confidence and morale.
"Unionistas must be congratulated, they have done an extraordinary job. We've suffered. It's a great goal. They don't seem like this division. Everything costs a lot."
On scoring from outside the area, Xavi also stated: "I turned around and said it. With such a low defence we have to act Frenkie, Pedri, Gündo, Oriol... they have to shoot. We have to do things better. Today we played a solid game.
"Koundé scores a great goal. But we must take a step forward."