As if the task of taking on Barcelona in the Nou Camp were not hard enough, Arsenal have to do it with injury ruling out key players. It's a job and a half with a full squad, but with the injuries Arsenal have got it is going to be a lot more difficult.
Losing Alex Song is a bigger blow to Arsenal than losing Cesc Fabregas. Song's strength in the holding position in the midfield would have been a key factor in Arsenal's plan, and now his place will be taken by someone not as capable. If there was one player I would want at the Nou Camp, above all others, it would be Song. Not Fabregas.
When you play at the Nou Camp you have to accept that Barcelona will have the ball for a large percentage of the game. So how you play when you don't have the ball is even more important than usual. That's why it is such a huge blow to lose Song. In the likes of Fabregas, Jack Wilshere and Samir Nasri, Arsenal have the players who are capable of causing damage when they have the ball. They are comfortable on the ball and have the talent to create something in the final third of the pitch, which might potentially result in an away goal. There is no doubt Arsenal have the attacking talent to do that.
But it is the defensive point of view that concerns me. Song is someone who performs the holding role in midfield without thinking about it and his absence leaves a huge hole.
Abou Diaby and Denilson both played against Sunderland but neither is as good as Song. Denilson would get my nod over Diaby, who looked laboured on Saturday. Denilson has improved since he first arrived at Arsenal, but because he has not developed as fast as some of the other players around him, it might look like he has stood still. One area he has improved has been knowing what's behind him, because that stood out as a weakness when he first came into the team.
He will certainly need to know what is going on at the Nou Camp tonight because Barcelona will be looking to capitalise on any confusion in the Arsenal defence. They like to play the ball in front of the defence, suck players into making a tackle and then hit you with the ball behind you. They did that for almost half an hour in the first half at the Emirates – and that was with Song.
In the first leg, Laurent Koscielny did well in the second half, when he followed Lionel Messi as the Argentine dropped deeper, but he will have to make the right calls tonight on when to go and when to leave him. If he is not careful players will run off him and get in behind.
All over the pitch it will be like individual games of chess. Players need to work out when to put their foot in and when to drop off. And if they do make mistakes, there is every chance they will be punished. It is unlikely that Arsenal will keep Barcelona out for the full 90 minutes, so I think they will have to score to go through.
I would pick Marouane Chamakh up front – he looked lively when he came on against Sunderland. I would also go for Andrei Arshavin on the left, and Nasri on the right.
Arsène Wenger trusts his players to do their job and they have every chance. But it will be very difficult. When you play at the Nou Camp it feels like the biggest pitch in the world. The fans are very noisy, but also are reasonably patient because they know Barcelona usually win in the end.
My XI: Szczesny; Sagna, Djourou, Koscielny, Clichy; Denilson, Fabregas, Wilshere; Nasri, Chamakh, Arshavin.