They played very very well in their 1-1 in the first leg against Barcelona a week ago, and played just as well in a 2-2 draw against Real Madrid at the weekend. Within half an hour, it was dead and buried. Already it was looking like a massive ask for Celta, who were being torn about by a vintage Barcelona display.
Celta have no injury concerns ahead of the game.
Luis Suarez took advantage of a poor back pass three minutes later to make it 4-0 and end any chance of Celta getting back into the tie.
It gave Barcelona a 4-0 lead at half-time, with their place in the last eight effectively secured.More news: Queen's bra-fitter says book cost company royal warrant
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Manager Juan Carlos Unzue will be hoping for another big showing from his players at the Camp Nou, but whether they can produce a third high-intensity performance in a week remains to be seen, and it will be tougher for Celta on Thursday as Barca boss Ernesto Valverde is likely to field a stronger line up than he did in the first leg.
The tie petered out in the second half but French global Ousmane Dembele showed why Barcelona paid 105 million euros for him previous year when he dribbled past three defenders from the halfway line before being denied by a desperate tackle.
2-0 up in the match, Barcelona did not push much in the second half but Paulinho tapped in the ball in the extra time to score his seventh goal in the league. It was another encouraging sign for Barcelona, with the Frenchman continuing his recovery from a recent injury layoff.
Barca eventually claimed a fifth on the night to compound the visitors' misery, Ousmane Dembele lifting a corner into the box for Ivan Rakitic to bury home with a free header into the top corner of the net from 10 yards out.
New £145million signing Coutinho was not named in Barca's squad.