Barcelona manager Hansi Flick conceded that Paris Saint-Germain were worthy winners in their 2-1 Champions League victory at the Montjuic Olympic Stadium on Wednesday and said that his team needed to improve in key areas.
Speaking at the post-match press conference, Flick acknowledged that his side, who took the lead through Ferran Torres in the 19th minute, were second-best for much of the contest.
PSG, despite missing several key players, equalised through 19-year-old Senny Mayulu in the first half before substitute Goncalo Ramos scored a 90th-minute winner.
"Today, I don't think we can say we're on the same level," Flick admitted. "I believe in my team, but today we didn't show our best side. After 35 minutes, PSG took control of the match. I don't think we played to our full potential. But that's also important in the Champions League. They deserved the win."
Flick pointed to fatigue as a factor in Barcelona's struggles during the second half, where PSG dominated possession and created the more dangerous opportunities.
"I think you could see in the second half that some players were very tired," he explained. "When you're a bit tired, it shows on the pitch. But everyone gave their all on the pitch. With the score at 1-1, you have to have better structure in defence. We have to learn and improve."
The German manager also emphasised the importance of maintaining defensive organisation and making better use of possession, praising PSG's ability to exploit spaces and impose their game.
"We lacked structure in the second half," Flick said. "But when I see a player like Eric (Garcia), who had a fantastic game, I love it. We have to train, improve, and it helps us a lot for the future."
"You have to hold out for 90 minutes, the whole team has to defend, attack, play at a high level with the ball, take advantage of spaces, participate in possession... At PSG, you saw that everyone knows how to take advantage of spaces, wants the ball... these are things to learn and improve on."
Reflecting on the final stages of the match, Flick expressed frustration with his team's inability to see out the draw, as PSG capitalised on a defensive lapse to snatch the victory.
"Of course, we are disappointed," he admitted. "When you're defending a 1-1 draw, you have to play more intelligently at the end of the match, and that didn't happen. They scored against us on a transition. We have to be more organised and cover all the spaces. We are very disappointed, which is normal because we wanted to perform better today."
Barcelona will look to regroup ahead of their next Champions League fixture, a home game against Olympiacos in three weeks, when PSG travel to face Bayer Leverkusen.