Robert Lewandowski described Barcelona’s defeat to Borussia Dortmund on Tuesday as “a good lesson to all of our young players”.

Barcelona advanced to the Champions League semi-finals despite losing 3-1 to Dortmund at Signal Iduna Park in midweek. The Catalans boasted a 4-0 advantage from the first leg but flirted with an unlikely elimination as Dortmund racked up chance after chance.

“This match can be a good lesson to all of our young players,” Lewandowski warned. “Champions League is Champions League and you always have to be prepared… not at 90% or 95%, no. 100%.”

At 36, Lewandowski is the most senior member of a youthful Barcelona squad. Half of the outfield players who started against Dortmund were 23 or younger, while the club’s star forward Lamine Yamal is still not legally an adult. Yamal was 11 the last time Barcelona reached the final four of the Champions League.

“We gave Dortmund a lot of opportunities to create chances and score,” Lewandowski continued. “Maybe this is what we needed to wake up; we have to learn from what happened.”

Barcelona had not suffered defeat in any of their first 24 matches across all competitions to start 2025. That run – which was the fourth-longest in the club’s history – came to an end on Tuesday without denting their ambitions of lifting the Champions League title. “If we had to lose and make mistakes, it’s better to have done it now,” Lewandowski admitted. Although, he quickly added: “There’s no room for so many mistakes going forward.”

Manager Hansi Flick was also keen to highlight the positives. “There wasn’t a great atmosphere there,” the German said after coming out of Barcelona’s dressing room. “But then I said: ‘Guys, it’s time to cheer up, we are in the semi-finals of the Champions League and we have to celebrate it now!'”

The Catalan giants will be up against one of Bayern Munich or Inter who face off at San Siro on Wednesday evening.