Blaugrana keeper Victor Valdes has admitted he doesn't know the Arsenal forward, but the Moroccan international must be respected because of the club he plays for.

"I don't know him, but if he is at Arsenal he must be good. I will be wary of him," Valdes told Le Parisien.

"We will wait for the team news to be sure that Van Persie won't play. Apart from the coach of Arsenal, nobody knows who will play."

Wenger does have the option of Danish forward Nicklas Bendtner, who has been performing well of late in front of goal and scored against Barcelona last season in the Champions League. But the French tactician may still have a trick up his sleeve in calling on his potent Dutch striker.

Arsenal will look to defend their 2-1 aggregate lead when travelling to the Camp Nou for tonight's 20:45 CET kick-off.

The French defender Gael Clichy thinks that Arsenal are a far different proposition to the team that got beaten 4-1 at the Nou Camp last winter, and they are more than capable of getting a result tonight.

He thinks that the Gunners have grown in confidence since they finally broke the voodoo of losing to Chelsea in the Premier League, and even though he is extremely impressed with Barcelona, he is sure that Arsenal are the team to beat them.

“I have watched the first leg against Barcelona again three or four times.” Clichy said. “I am rarely impressed by a team but this time Barcelona got 60 per cent possession on our pitch.

“It is huge. We suffered but we could resist.

“Something happened against Chelsea. Since that match we are not the same team anymore.

“Everyone makes an effort, so it is a little easier on defenders. In the past, sometimes two or three players could give up. At such a level, it is not possible.

“What will happen at Camp Nou? We will qualify and I will score! It would be nice.

“We will give our very best. Arsene Wenger has often told us there is no better team than ours.”

That’s the spirit Gael. just believe and it will come to pass……

If Nicklas Bendtner is right and football is often like a boxing match, then Arsenal need to invoke the spirit of Muhammad Ali's famous 1974 Rumble in the Jungle victory over George Foreman to ensure success in the Nou Camp.

"Let him burn himself out, let him blast his ass off and pray he keeps throwing. Let it be a matter of who hits who first, and that's me," Ali later recalled as he defied critics by beating the man regarded as indisputably the best in the world.

Barcelona are rightly anointed with a similar description and they will throw everything at Arsenal in a bid to overturn a 2-1 first-leg deficit following an enthralling night in north London.

It is a proposition to make even the most experienced opponent wince, let alone a goalkeeper barely out of his teenage years whose ability and self-belief have been seriously tested for the first time.

Any momentum created by that superb comeback victory over Barca was decidedly checked at Wembley, where Wojciech Szczesny faltered in one calamitous misunderstanding that gifted Birmingham the Carling Cup.

Question marks have reappeared over Arsenal's mental strength and their ability to ally style with substance as the trophyless run goes on.

There is little respite these days. Sunderland proved determined visitors with a defensive resilience that went unbroken but, here in Catalonia, Arsenal face the antithesis of that challenge.

Barca will lay siege to Arsenal's goal tonight in front of 95,000 baying fans, unbeaten in their last 20 home games and motivated by a sense of revenge.

Lionel Messi, last year's tormentor, has 46 goals this season and underperformed by his own heady standards in the first leg; any Arsenal weakness is likely to be savagely exploited.

But Szczesny said: "I don't think our confidence has been shaken by what has happened in the last 10 days.

"We lost the Carling Cup Final and missed an opportunity to win a trophy. It just gives us more desire and makes us more hungry to go and win the other ones. We made a mistake and we move on from it. It just makes me more determined to win rather than drop my confidence.

"We will have a lot of responsibility defensively because as a team they play a lot of attacking football and create a lot of chances. To keep a clean sheet against Barcelona is a very tough task. But we believe we can do it and we also know we can score if we need to.

"It will be very important that we talk to each other a lot when the stadium is that big and that loud, so you have to deal with it. If you can't hear each other you have to talk to each other with our body language, show our confidence and show where we want the ball and who to mark.

"Playing in the Nou Camp is a massive thing because as a kid you always dream of playing in stadiums like that. This is what you play football for.

"Sometimes you have games away up north against teams you don't really fancy playing against and sometimes you have big games that you are desperate to be a part of.

"I am confident I can handle it in the same way I believe the team is capable of getting the result we need."

Optimism created by success in the first leg is tempered by memories of last year's trip to the Nou Camp, where Bendtner briefly raised hope before Messi tore Arsenal to shreds with four goals and a performance that will have scarred many in red and white.

Szczesny, perhaps, benefits from not being among them as he was then in the middle of a seven-month loan spell at Brentford and had played in a goalless draw at Exeter the night before the Messi mauling, which the Poland international watched on television.

Although scars from that chastening night remain - not least a squad depleted by injuries - there have been signs of progress that would develop into emphatic realisation were Arsenal to progress to the quarter-finals.

"Barca had probably the best side in the world at the time and they got the result they deserved," Szczesny said. "But we believe and are completely confident that this year is going to be a different story.

"We are a better side now, there is no doubt about that. We showed that in the first leg we are capable of playing good football against them and that we can beat them.

"I think we have added some quality to the team and that has made a big difference. They are beatable and we have no fear because we know we can do it.

"They have fantastic players and they are fantastic team. Messi is a great player and there are many reasons why people call them the best side in the world. But people can make too much of great players - even the very best - and we showed that in the first leg.

"We beat them at home and we believe we can do the same tonight.

"If you manage to beat the best side in the world and reach the quarter-finals, people are going to realise we are one of the best teams in Europe. We can prove people wrong."

Barcelona will be without first-choice central defenders Gerard Piquet, who is suspended, and Carles Puyol, who has tendonitis in his knee.

We've known for a long time that Arsenal can float like a butterfly but tonight we'll find out if they can sting like a bee.