Barcelona were twice punished from set pieces, yet Flick highlighted the character his side showed to regain control of the match.

"After conceding two goals from set pieces, we came back and that's good," Flick said. "The reaction was important."

The German coach stressed that the contest was never straightforward, pointing to the conditions and the strength of the opposition.

"It wasn't easy to play today. It was very cold and Slavia played very well," he explained. "They're a very physical team, with dangerous transitions and balls. We were especially better in the second half."

Attention then turned to Pedri, who was forced off during the second half. Flick confirmed there was still uncertainty around the midfielder's condition.

"I don't know exactly what it is. I don't know how long he'll be out for. It's not good news. We'll see tomorrow," Flick said.

Flick also underlined the impact of Dani Olmo, whose introduction helped settle the game. "Olmo came on and scored a goal. The substitution was a success, and the fourth goal came at just the right moment."

The Barcelona boss was full of praise for Fermin Lopez, who continues to impress after choosing to stay at the club.

"He's a fantastic player. I'm happy he stayed," Flick said. "He breathes Barcelona DNA. I really appreciate his performance today."

Asked about Barcelona's defensive lapses, Flick remained calm. "Two mistakes on two corners. It was just one game, and we can improve. We want to and we can improve."

Looking ahead in the Champions League, Flick acknowledged the challenges still to come. "It won't be easy to beat Copenhagen. We don't know how Ferran will be, maybe Pedri won't play. Lamine is back, but De Jong won't be there," he said. "We have a good chance of being among the top eight."

Flick also singled out Ronald Araujo and Frenkie de Jong for praise. "Araujo showed his speed in the duels. Step by step, he's becoming more integrated," he said. "De Jong played well. His level is very high, not only in defence, but also in attack."

Ousmane Dembele scores as Barcelona beat Real Sociedad to reach Copa del Rey semis