Barcelona coach Hansi Flick insisted his team must learn how to defend better after conceding a last-gasp winner against Champions League holders Paris Saint-Germain on Wednesday.
The French side struck in the 90th minute through Goncalo Ramos to claim a 2-1 victory at the Olympic stadium in the league stage clash.
Barcelona's high defensive line was unpicked with Achraf Hakimi racing in and crossing for Ramos to finish, and Flick admitted PSG were operating on a higher level.
The Catalans were knocked out in the semifinals of last season's Champions League by Inter Milan as their defensive deficiencies were exposed, conceding seven goals across the two legs.
"With (the score at) 1-1 you have to defend better, have a better structure in the defence," Flick told reporters.
"We will learn this and we have to make it better next time against this quality of team."
HONEST FLICK
The German coach said PSG deserved to win the game and that his team were below their best and could not match the European champions on the night.
"There is no point in saying we are on the same level (but) I believe in my team – today wasn't our best day," continued Flick.
"We train to get better and better and this game today (will) help us a lot, also for the future. The whole team has to defend, the whole team has to attack...
"The philosophy that they (PSG) have, is fantastic. They have young players, they had high quality and speed on the ball, very, very good."
Flick said when his team were playing at their best they could match Luis Enrique's side.
"We could see today how the level of PSG is, I'm 100 per cent sure we can play like this," added the coach.