Arsene Wenger accepted his Arsenal side must be more ruthless against Barcelona than they were against Hull when the Champions League holders arrive at the Emirates Stadium on Tuesday.
Wenger’s team were left frustrated as they were held to a scoreless draw by second-tier side Hull City in the fifth round of the FA Cup ahead of the first leg of their Champions League last 16 tie against the Catalans.
The combination of a fine display by Hull goalkeeper Eldin Jakupovic and Arsenal’s failure to make more of the chances that came their way meant the two teams must now face a replay.
"We need to be more efficient in the final third because today we have more than 70 percent possession and we will not get that on Tuesday night (against Barcelona)," said Arsenal manager Wenger.
“So that means we will have to be more efficient because we will not have as much of the ball," added Wenger, whose team are bidding to become the first club since the 19th Century to win the FA Cup three years in a row.
"I was excited about the game today but of course Tuesday is an exciting game," said the 66-year-old Frenchman.
“We started favourites today (Saturday), we won’t be on Tuesday night so on Tuesday night we need great solidarity because we need to defend well, we know that, and make the maximum of our possession what we didn’t do today.”
Wenger made nine changes to his starting line-up, and left Mesut Ozil and Aaron Ramsey out of the matchday squad altogether.
The manager revealed Ozil has been suffering from a cold all week but insisted the Germany international would be fit to face Barcelona.
"I think I played a team that in my opinion had the quality to win the game and the Barcelona game was not in my mind," insisted Wenger.
"I rested Ramsey and Ozil completely because they have played many games from the start of the season and when I can do it, I do it.
"Ozil was a bit sick over the week so I decided to leave him out and Ramsey has played many times. Ozil will be alright. He had a cold. It’s nothing major."
Hull manager Steve Bruce, whose side lost the 2014 FA Cup final to Arsenal and were knocked out of the tournament by the Gunners last season, made changes for the tie and called for an end to replays in the competition –- although Wenger took the opposite view.
“Is a replay a nightmare? No. A nightmare would have been to go out," said Wenger. "The frustration is not to score."
But Bruce said: "There is no more of a traditionalist than me when it comes to the FA Cup but why can’t we just go to penalties? Why do we have to have a replay
"Supporters have to find the money to support their team. In the past to win a European cup you had to play six or seven games, now it’s 17.
"We all love the FA Cup and for our club, the final was the biggest day in our lives," added Bruce, three-times an FA Cup winner as a Manchester United defender.
"We play Ipswich on Tuesday and you know when you come to the Emirates you are going to have to run a million miles.
"A footballer can play three games in three days if he wants but you can’t play with the energy or intensity that you need to win a Championship game or an FA Cup tie."
An exasperated Bruce, whose team are top of the second-tier Championship, continued: "We have a game on Tuesday and then on Friday. Then the following Tuesday then Friday again. It's ridiculous the number of games we have got coming up."