The holders visit Barcelona on Wednesday and 18-year-old winger Yamal is keen to shine after finishing as runner-up at the Ballon d'Or gala last week, behind PSG's Ousmane Dembele.

Yamal returned from a groin injury on Sunday against Real Sociedad in La Liga and provided an assist a minute after coming off the bench during a bright second-half cameo.

"(Calling him) super, super, super... I don't like this... he's 18 years old and for me he also has to focus on working hard," Flick told reporters.

"It's not always easy, with talent you can get to this point, but to reach the next level, one or two steps more -- and I think he's able to do that -- he has to work hard."

Last season Barcelona won a domestic treble of La Liga, the Copa del Rey and the Spanish Super Cup, but fell just short in the Champions League, beaten in the semi-finals by Inter Milan despite two sensational displays by Yamal.

Against Luis Enrique's attacking PSG side Flick demanded Yamal and his team-mates knuckle down when the French champions are in possession.

"It's not only about playing with the ball, it's also defending," continued Flick.

"This is what we need from every player -- even a great player with the ball like him -- and this makes the difference."

Flick said to beat PSG his team had to concentrate from "the first second to the end of the match" and play at their highest level.

Paris Saint-Germain defender Achraf Hakimi said his team must club together to snuff out the threat of Yamal on Barca's right wing.

The Morocco international also said left-back Nuno Mendes has proved he can keep Yamal quiet, as he did for Portugal in the Nations League against Spain in June.

"He will have to play against the best left-back in the world, Nuno Mendes," said Hakimi.

"He's already proven he's capable of stopping Yamal, as he did before, and stopping other attackers who have a similar playing style.

"I think the strength of our team is the support we give each other. We'll try to help Nuno Mendes, not leave him one-on-one, because we know Yamal's ability."

- Rashford has 'arrived' -

Flick also praised Marcus Rashford, who has established himself on the left flank for Barca.

With Raphinha out injured, Rashford is set to start against PSG. The forward, on loan from Manchester United, netted twice in Barcelona's opening Champions League win at Newcastle.

"Everyone can see it in the last games, the Newcastle match gives him a lot of confidence and now he's here, he's now arrived in Barcelona," said Flick.

"This is not always easy, to come to La Liga... with different opponents, a different style of how we play football, he's adapted (well)."

PSG will be without first-choice attackers Dembele, formerly a Barca player, Desire Doue and Khvicha Kvaratskhelia, among other missing stars.

Barca midfielder Pedri said he considered his team favourites to win the game.

"PSG are one of the best teams in the world, and we are the best -- or at least that's how I see it," he told reporters.

The French side beat Barca 4-1 the last time the teams met, in the 2024 quarter-finals, after Barca defender Ronald Araujo was sent off. PSG progressed 6-4 on aggregate.

"Every Barca fan knows that we were close to going through two seasons ago," said Pedri.

"There's always revenge in football and that's what we want -- it's the kind of game that's most enjoyable."