Barcelona manager Hansi Flick has defended Lamine Yamal following a difficult Champions League performance against Chelsea, while also challenging the teenage forward to "step up" and prove his quality. Flick acknowledged the difficulty of facing Chelsea defender Marc Cucurella, whom he described as "one of the best in the world," but insisted that Yamal needs to lead the team's recovery from their 3-0 defeat.Yamal endured a difficult night against Cucurella as Barca were overpowered at Stamford Bridge and ended up being substituted with 10 minutes left. The winger's reaction to his withdrawal sparked caught attention in the media, but Flick moved to defend the 18-year-old and stressed he expects better against Deportivo Alaves on Saturday."Lamine is fine and feels good. Many players aren't happy when we substitute them," he said at a press conference. "I was a player myself, and many times I didn't react as I should have. Cucurella is one of the best full-backs in the world; he's a very good player. But, for me, now it's Lamine's turn to step up and show that we need to forget the Chelsea game. This is when he has to show how good he is."Barcelona's 3-0 defeat at Stamford Bridge was a significant setback, with an own goal from Jules Kounde and strikes from Estevao and Liam Delap condemning them to a heavy loss. The result left them in 18th place in the Champions League group stage table with seven points from five matches, placing them in the play-off positions rather than the automatic qualification spots.Flick admitted the defeat was "tough" and that the team was "feeling down," but he refused to solely blame the defence for the result. "When we lose and when we concede three goals, it's easy to say it wasn't a good match or that it wasn't the Barca we'd like to see. Ultimately, some people don't understand what we need to play with that high defensive line," he explained. "It's our own style; it's not just about the defenders. The forwards and midfielders also initiate the press. That's what I need from the players. The blame seems to fall on the defense, but that's not fair. If we don't all press effectively, we'll have problems, I want to make that clear."Looking for smarter football bets? Get expert previews, data-driven predictions & winning insights with GOAL Tips on Telegram. Join our growing community now!Ahead of the league fixture against Alaves, Flick provided updates on several key players. He confirmed that Ronald Araujo will miss the match due to a stomach virus, adding to the defensive concerns after his red card against Chelsea.Midfielder Fermin Lopez is also out after feeling discomfort following the match at Stamford Bridge. "The tackle from Athletic Club affected him, but he wasn't seriously injured. It was after the Chelsea game that he felt discomfort. There's no other explanation. This is football, and things like this happen. Sometimes it's related to new boots. Now they have a new color every month," Flick stated.However, there was positive news regarding Pedri, who is expected to feature as a substitute in the second half as he continues his return to full fitness. Flick also mentioned that Marc Bernal, returning from injury, will get playing time, and Andreas Christensen could be an option in midfield, where he has been trialled alongside Eric Garcia.Raphinha, who Flick described as "one of the most focused players on the team," is also keen to make an impact after the coach admitted he had missed the Brazilian's influence.Barcelona face Alaves at Camp Nou in La Liga on Saturday. Flick stressed the importance of securing three points to maintain their lead at the top of the table. "Our goal tomorrow is the three points. Anything else is secondary," he said. Following the domestic fixture, Barcelona will look to improve their Champions League standing in their remaining group matches to secure a more favourable position for the knockout stages.