Barcelona midfielder Xavi has accepted that his side are going to experience hard times as they go in search of the Champions League title.
The Blaugrana reached the last eight with a 4-1 aggregate victory over Manchester City, but were made to work hard for a 2-1 victory over Manuel Pellegrini's side during Wednesday's Camp Nou leg.
And the veteran midfielder believes his side have begun to recapture some of their best form, which will prove crucial as they look to mount a challenge for Europe's top prize.
"This is the Champions League and we know that at times we're going to have a hard time," he told the club's official website.
"I believe that we dominated the match, the sensations are good and the objective was to reach the quarter-finals - here we are, pleased with our victory.
"Our rivals also play, but we tried to have the ball and play our football.
"The coach is the one who decides how to play, and we have a big team and we're playing well. We've recovered our form.
"The fans were sensational and the atmosphere was extraordinary."