The Gunners will start as underdogs when they play hosts to the reigning champions at the Emirates Stadium on Tuesday evening, having failed to score in four of their last seven games in all competitions.
Barcelona are on the hunt for their second consecutive treble under Luis Enrique, boasting Europe's most feared forward line in the shape of Lionel Messi, Luis Suarez and Neymar.
And Wenger says keeping them quiet remains the priority for Arsenal if they stand a chance of reaching the next round, admitting conceding an away goal in the Champions League is like a “knife in your heart”.
“I think we will score so I am not too concerned,” he said. “It’s true that recently our goals have dried up a bit and we have to find a way to get that going again. But I am more concerned about stopping them from scoring because at home in the Champions League nil-nil is not a bad score.
“We have always made it difficult for ourselves in previous years by conceding goals at home and the rules of the modern European Cup encourage teams to defend at home and attack away because of the importance of the away goal.
“Many times I have said that should be suppressed because if you concede a goal at home in the Champions League it’s a knife in your heart every time. Against big teams it becomes very difficult.”
Arsenal have bowed out of the first knockout stage in each of the last five seasons but while Wenger has put importance on keeping a clean sheet in the first leg, he has dismissed the idea that he will switch to a more defensive-minded team against Barcelona.
“It’s against my nature,” added Wenger.
“I cannot go into a game and think I will just play for a zero-zero. I don’t believe you can say you are a big club and just want to defend.
“On the other hand, Barcelona are a very offensive team so to give ourselves no chance at all of scoring against them would make us guilty as well.
“We have to try to score against them because if they have a vulnerability, like us, it is defensively, as it is with any offensive team.”