By Richard Clarke in Barcelona

This may be only the last eight of the Champions League but, for Arsène Wenger, Barcelona are very much the final hurdle.

Arsenal have spent the last decade visiting Europe's elite. In that time they have rattled up some famous wins on the road. Victories at Inter, Milan and Real Madrid represent arguably the Club's finest nights on the Continent. But Barcelona are the biggest scalp.

In the build-up to tonight's tie at the Nou Camp, Wenger admitted Pep Guardiola's side were the best team he had ever faced. After their first-half display at Emirates Stadium last week, it is an entirely understandable view.

The pass-masters were beaten at their own game on their own surface. Ironically both goals by Zlatan Ibrahimovic came from long-balls in the second half. And Arsenal's late comeback leaves them in touch in the tie so a philosophical Wenger sees tonight's tie as a telling stamp in his footballing passport.

"I think we have won away in Europe against all the big clubs and the only place we haven't done it is here," he said.

"But life is about grabbing your opportunities and this team can make history by grabbing the opportunity. I will be especially proud if they do it and I know they will fight for it.

"I have always supported this team even in weak periods of the season because I feel they have some exceptional mental strengths and, of course, they will be needed.

"At the moment Barcelona are the best team in Europe and we have to show that we can beat them. It's important we go there with the right attitude. We know that we have to turn up with 120 per cent commitment, but also intelligence."

Later in his pre-match media work Wenger was asked if like, Cesc Fabregas, he thought Barca were the best team he had faced.

"Yes," he replied, "because they play at a higher pace collectively. And I don't think we have ever been dominated so much at home. Certainly Cesc hasn't! He is used to having the ball.

"I think there was the psychological influence of us being so used to having the ball suddenly not to have the ball, certainly the impression was deeper on the players than it should have been."

Both sides suffered key casualties in last week's game and then were dealt another blow at the weekend. Arsenal lost Cesc Fabregas (cracked fibula), William Gallas and Andrey Arshavin (both calf) to injury on the night. Barcelona saw their two centre backs - Carlos Puyol and Gerard Pique - suspended. Ibrahimovic suffered a calf injury in the warm up to the game against Athletic Bilbao at the Nou Camp on Saturday evening. That came shortly after Alex Song had left Emirates Stadium hobbling. It transpires that the midfielder inflamed knee ligaments in the 1-0 win over Wolves.

Wenger is still sweating on Sol Campbell's hamstring and Tomas Rosicky's knee. But the manager's general demeanour suggested they would start. A late pull-out could be costly, Arsenal's bench is already short on experience and/or match sharpness. Remember, substitutions have been THE defining factor in those late, late wins recently.

"I've never had so many injuries before such a big game," said Wenger. "But that is why football is interesting. It's never boring.

"Also the quality of Barcelona gives me an extra excitement, because we all expect a good game. The first game was very promising and responded to people's expectations. People are waiting with excitement because they know they'll see another interesting game and I'm sure we will."

"Interesting" really does not do justice to tonight. Inspired, emotional or tortuously tense are better labels. Arsenal fans are over here in numbers drinking in the atmosphere.

Barcelona are clear favourites but the visitors have been pulling off the incredible on a weekly basis recently. This, however, would top the lot.

The pessimist can point to that first half when Xavi, Guardiola's little Napoleon, calculated and re-calculated Barca's attacks with frightening speed. Only Manuel Almunia really repelled his army.

The optimist can concentrate at the final 20 minutes when Barcelona were put on the back foot. They appeared to run out of steam and, had Arsenal not been forced to carry the injured Fabregas, they would have gone for the jugular.

"At 2-0 down I felt we needed a miracle," he said. "But I know this team will never give up and knew that when we managed to get through their passing we always looked dangerous. I knew of course we could concede a third or fourth goal against a team like that but I always had hope.

"Now I think the momentum is with us. Barcelona could be disappointed because they were 2-0 up in a Champions League game and when you are pulled back it is very difficult to swallow. If the game had carried on a little bit longer I think we would have won so the key tonight is to start strong."

And to do that you must make sure you are not beaten before you begin.

Barcelona were utterly awesome last week but they did not put Arsenal away. Ironically they can be tried for the same football crime that Wenger's side commit from time to time - playing a beautiful yet wasteful game.

The romance of Nou Camp makes for great copy and Guardiola's men are a wonderful side (getting this far in preview without mention Lionel Messi tells you something of their overall strength). But if Arsenal are to be beaten let it be on the pitch not in the tunnel beforehand.

The final 20 minutes on Wednesday proved the holders can be pressurised and if the visitors begin this game like they finished the last then they can impose themselves.

"I think we were a bit inhibited in the first part of the game and the second half was much more balanced, when we came out and played at our level." said Wenger. "We have to first take into account the psychological part and then get a bit tighter in our marking.

"It's more down to us to turn up and not consider them too much. If we expect them to play weaker, maybe we will have a bad surprise so let's make sure we play better than we did in that first half.

"Last week, we were a little bit victims of the reputation of Barcelona. They have done it, we have not done it so you always make them bigger in our heads and, yes, they were very big."

Tonight, Arsenal attempt to bring Barcelona down to size.

Copyright 2014 The Arsenal Football Club plc. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source 6 Apr 2010