Arsene Wenger bemoaned Arsenal's worst performance of the season as they lost 1-0 at Norwich.
Grant Holt seized on a mistake from Vito Mannone to give the Canaries the lead inside 20 minutes and Chris Hughton's held on with little difficulty as the Gunners struggled to create a chance.
The Arsenal manager refused to condemn his players too strongly but was clearly disappointed with their Carrow Road efforts.
"Norwich had a good defensive performance, were focused and committed. We had a lot of the ball, but did not create much with it, which was a disappointing performance for us," he said.
"I felt we lacked a bit of sharpness. We missed what makes the success at the top level, that is complete focus and they were sharper than us.
"We do not blame anybody, [we] made many mistakes today. We have to put that performance behind us and realise that is not good enough.
"The attitude of the team has been excellent, but that was not at the level of what we have produced until now, it was the first time of the season we were way below par.
"We have to come out with a difference performance in the Champions League game (against Schalke) on Wednesday night."
There was at least some encouraging news for Arsenal as Jack Wilshere was on the bench after over a year on the sidelines through injury.
Wenger left the England international there as an unused substitute but insists he will feature soon.
He added: "I would have brought him on if the game had allowed it today, but it was too intense.
"He will play on Monday with the reserves and then we will see where we go from there."