Arsenal dominated before the break, with Viktor Gyokeres scoring and setting up Noni Madueke to give the visitors a two-goal advantage. However, their performance dropped significantly after half-time as Slavia fought back and threatened to spoil the night.

"We played at a really high level in terms of intensity, tempo, quality and clarity in what we had to do," Arteta said. "We were very efficient – we should have scored three, four or five."

The Arsenal manager was particularly unhappy with his team's reaction after the interval, insisting they had been warned about the challenge Slavia would pose.

"Right from the beginning of the half, we were extremely far from our standards, the basics, the concepts and everything we discussed to avoid," he said. "It was far from what we expect from each other, but we found a way to hold onto the result and win the game."

Arteta accepted responsibility for the decline, although he acknowledged the demands of playing three successive away matches in the Champions League. "It's a huge lesson, and we'll learn from the second half," he said. "I take full responsibility for the drop in the second half."

Gyokeres was a major positive for Arsenal, delivering a goal and an assist in a performance that pleased his manager. "I thought he was really good," Arteta said. "It's really great news for him, because he really needed that performance."

The striker also impressed with his movement and combination play, particularly against Slavia's man-to-man approach in midfield. Arteta praised his understanding of when to link up with teammates and when to attack the spaces behind the defence, describing his overall contribution as a great performance.

Asked about Gyokeres not starting every match, Arteta acknowledged that players naturally want regular football but stressed the importance of making an impact when opportunities arrive. "The players need to impact the game like he has done today when they get the opportunity," he said.

David Raya was also called into action as Slavia increased the pressure, producing important saves to protect Arsenal's advantage. Arteta praised the goalkeeper's quality but admitted: "We are concerned about what happened before that, which is something that obviously isn't what we've shown in the past."

There were fitness concerns surrounding Ezri Konsa, who was substituted after experiencing some issues following a demanding run of matches. Declan Rice, meanwhile, completed the full 90 minutes, with Arteta explaining that the midfielder had been rested against Fleetwood and had sufficient time to recover.

Arteta also praised Slavia's determination, organisation and belief, describing them as "an unbelievable team in terms of spirit" who continued fighting throughout the contest. Arsenal must now turn their attention to Saturday's Premier League meeting with Hull City at Emirates Stadium, with Arteta expecting his players to respond with a more consistent performance.

Real Madrid boss Carlo Ancelotti rules out any more signings