Per Mertesacker concedes Arsenal need to rediscover their best form for Tuesday's Champions League meeting with Barcelona following a disappointing 0-0 FA Cup draw against Hull.
Arsene Wenger's side dominated against the Tigers at the Emirates Stadium on Saturday but, unlike their FA Cup final meeting in 2014 and last year's third-round tie, they could not find a way to beat Steve Bruce's men.
Hull goalkeeper Eldin Jakupovic made several good saves to keep Arsenal at bay, with a replay not what either side would have been particularly keen on given their respective targets this season.
While Hull are gunning for promotion straight back to the Premier League, FA Cup holders Arsenal are challenging for the title.
They also have a Champions League round-of-16 first leg against Barcelona on Tuesday, and Mertesacker wants to see an improvement in the side when the Catalan club come to North London.
"Overall, we missed a bit of something and we have to come back quickly in three days' time,'' he said. "We have a very important game, the first leg against Barcelona, and we will see the fans again -- it will be another buzzing night but it is up to us how we perform.
"It is down to us. We produced a good defensive performance [against Hull] but overall in the final third, that little final pass at the end, we always rushed ourselves at times to finish, so we need to learn from that.
"We had a couple of good chances and we couldn't keep the pressure as high as we wanted, especially in the second half. We had enough chances to win, but we were unlucky at times.
"Overall it was disappointing, especially our finishing. We allowed [Jakupovic] to make some decent saves because we were not that decisive.''