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Raphinha led the line for Barca in its 2-0 win over Athletic Club on Friday (AEST) and scored the opening goal, while Fermin Lopez also got on the scoresheet.

Athletic goalkeeper Unai Simon was in good form as he made eight saves, and Flick admitted Barca could have won more comfortably if it had a recognised striker.

When asked if Raphinha was Barca's best option for the role, Flick said: "We don't know. For this match, yes.

"For me, it's important that when we have Raphinha or any other number 9, we can stick to our plan. Because of his pressing, his movement, his runs off the ball, his goal-scoring ability.

"For me, it doesn't matter what position he plays. He connects with the fans. He's very good, and I see many players involved. We have a very good atmosphere in the group, and that's necessary for us.

"Perhaps we would have sealed the win earlier today with a number nine. The important thing is that we created chances. I liked what I saw and we have potential. And we still have to improve."

Barca has also started its LaLiga campaign with back-to-back clean sheets, conceding just two shots on target across its two wins.

Flick, whose defensive tactics were criticised last season, highlighted the importance of having a strong backline.

"It’s very important. We have a plan, we want to play attacking football," he added.

"We played a great game, we created many chances, even though we only scored two goals.

"We need to be calmer and not always try to finish, without rushing things in certain situations, like when we went down 1-0. We have to keep possession.

"We defended very well. I like the level of our play, but we have to improve."