Luis Enrique’s side pulled off the greatest comeback in the tournament’s history after coming back to beat the French champions 6-1 at Camp Nou.
However, they face a different proposition entirely against Juventus who have conceded just two goals in the competition so far and none in their last 441 minutes.
“We got things wrong especially in the first half for us, and in the Champions League you get punished as we did with two goals," he told Barca’s official website.
"The second half was a different story and we really deserved to get a goal back.”
“You can concede goals like that from corners and Juve are a good team, and if you don’t get it right against teams like that then you pay the penalty.
“It’s not quite as bad as it was in Paris, but we do have another uphill struggle ahead of us.
"If we do what we have to do we can turn this tie around, but if we don’t then it’s going to be impossible."