Barcelona head coach Hansi Flick remained upbeat despite his side kickstarting their Champions League campaign with a defeat to Monaco on Thursday. 

The visitors were dealt a blow with just 10 minutes on the clock after defender Eric Garcia saw red after a tangle with Takumi Minamino on the edge of the box. 

Monaco made the most of their man advantage six minutes later when Maghnes Akliouche struck beyond Marc-Andre ter Stegen. 

Lamine Yamal levelled the scores before half-time, becoming the second-youngest player to score in the Champions League with a low finish into the bottom corner.

However, substitute George Ilenikhena would hand the French side the victory in the 71st minute, compounding Flick to his first defeat as Barca head coach. 

It was also Barcelona's third ever defeat in their opening game of the competition after 1997-98 (2-3 v Newcastle) and 2021-22 (0-3 v Bayern Munich). 

Despite the loss, Flick had already switched his focus to this weekend's LaLiga fixture against Villarreal and is looking for a response from his players.

"With (Garcia's) red card the game changed totally, but I can see the positives," Flick said. 

"We tried to defend as a team and attack as a team. We had chances but they deserved to win.

"I have told the team to lift their heads up because they are disappointed, but we have to focus on Sunday, which is our next game.

"It's the time to recover. Hopefully, players will be back with a lot of energy.

"We have players that gave more than 100 percent, every player tried to give their best in this situation.

"I'm really proud of this team but we have to accept how we lost today."

Garcia's dismissal proved to be decisive in deciding the contest, with the Spaniard's sending off the earliest in the Champions League since Oleksandr Kucher for Shakhtar Donetsk against Bayern in 2015 (third minute). 

Barcelona's last red card in the competition came in their quarter-final defeat to Paris Saint-Germain last season, with Ronald Araujo shown his marching orders in a 4-1 defeat to the Parisiens. 

The Spaniards have failed to reach the semi-finals of the competition since their dramatic aggregate defeat to Liverpool in 2018-19, but Flick remained confident about their chances this time around. 

"Today you see this situation with a red card after 11 minutes, it changed our match plan, we have to accept it, this happens," Flick concluded. 

"But we are strong enough to play a good Champions League, we have seven matches ahead, and I think we will win many matches."