Song ruled out but Wenger optimistic Arsenal can make progress

The Gunners' preparations for the second leg were yesterday hit by the news Cameroon international Alex Song – who had been in line to drop back into defence as veteran Sol Campbell struggles to regain full match fitness – was out with a knee injury.

Arsenal were already missing captain Cesc Fabregas, who suffered a cracked bone in his leg when winning the late penalty which levelled the tie at 2-2, as well as centre-back William Gallas and Russian playmaker Andrey Arshavin.

However, Wenger maintains his team – with England forward Theo Walcott in contention to start having made a major impact from the bench in the first leg – have what it takes to pull off another famous away victory on one of Europe's biggest stages as they look to capitalise on Barcelona's own selection problems.

"We have won away everywhere in Europe. Barcelona is a place where we have not done it, so there is no better opportunity (than tonight)," Wenger declared. "I am confident despite the injuries we have that we can do it. Of course, we will need to get everybody to 100 per cent of his potential and have a great team performance.

"This team, though, has such a great mental strength and I believe they can fight against the odds anywhere in the world."

Wenger openly admits Arsenal are lucky to still have a chance, however slim, of progression to the semi-finals after the way in which they were completely dominated by Barcelona during the opening stages of the first leg last week.

However, after the Spaniards had gone 2-0 up following a brace from Zlatan Ibrahimovic – who will miss tonight's game because of a calf injury – the Gunners somehow fought their way back to level.

Wenger expects another intriguing encounter.

"Barcelona certainly have learned from the first game it will not be an easy task for them," he said.

"We have learned that it is important we start with full power, without any inhibition, which we showed in the first 20 minutes at the Emirates.

"How we manage to do that will certainly have a big influence on the game and on the result."

Barcelona have not won any of their last five home meetings with an English side, including goalless draws against both Chelsea and Manchester United in the last two seasons, while Liverpool recorded a victory at the Nou Camp in February 2007.

Central-defensive pair Carles Puyol, their captain, and Gerard Pique are both suspended. Andres Iniesta is again struggling to be fit after missing the first leg and did not feature in the 4-1 win over Athletic Bilbao at the weekend.

Wenger, however, said: "I do not think there is any reason to speculate on weaknesses when you look at the opportunities and possibilities they had in the first leg.

"Also, they have plenty of centre-backs still available.

"I believe it is more important we focus on our side and how well we want to play.

"We have to try to be very disciplined, but not to hide when we have the ball."