Arsenal claimed a slender 1-0 Champions League win over Shakhtar Donetsk at the Emirates Stadium on Tuesday night after which manager Mikel Arteta admitted his side looked tired.
The Gunners bounced back from their surprise defeat against Bournemouth after Gabriel Martinelli's first-half strike rebounded in off goalkeeper Dmytro Riznyk to maintain their unbeaten record in Europe.
But Leandro Trossard missed a second-half penalty and David Raya had to produce a fine stoppage-time save to be sure of the three points. Arsenal's evening was also soured when Riccardo Calafiori limped off with a knee injury in the second half.
Arsenal hosted Shakhtar just 72 hours after playing one hour with 10 men in their 2-0 defeat at the Cherries, with Liverpool – who they trail by four points in the Premier League – up next at the Emirates on Sunday.
"The first half we were very dominant and we created four big chances that we should have converted and put the game to bed," said Arteta.
"The second half was very different and we looked tired, and lacked that sharpness, with and without the ball. We missed a penalty. And that emotion was difficult to overcome. We had to dig in. But overall it's Champions League, get the win, clean sheet. Let's move on."
However, Arteta insisted he expects his side to be back on song when Arne Slot's side visit on Sunday.
He added: "We played two nights ago, with players coming back from internationals, after flying from Brazil and many countries.
"I was expecting a bit of a drop-off. And the fact that we put so much in the first half and didn't get the distance in terms of the scoreline, we paid a bit for that.
"Then we made life more difficult for us because we started to give the ball away in not the right areas and then it was more open. That didn"t help. But we have now four days. And believe me, come Sunday we'll be flying. We'll be in the right place."
With captain Martin Odegaard sidelined, and William Saliba and Bukayo Saka both set to be out for the visit of Liverpool through suspension and injury respectively, Calafiori added to Arteta's woes after he was withdrawn in the second half.
Calafiori appeared to twist his knee in a collision with Eguinaldo and although he attempted to carry on, he was withdrawn six minutes later.
Ben White, who only returned from injury in the defeat at Bournemouth following a near-month lay-off, was substituted at half-time. However, Arteta revealed that was a precaution with the defender already on a yellow card.
"With Ben, it was my decision to take him out," added Arteta. "He had a yellow card and we've played enough with 10 men in recent periods.
"They had a lot of players on that side, so I didn't want to take any chances there.
"With Riccardo, he had to come off because he felt something. I don't know the extent of it so in that sense that's not great news."