We all love watching Barcelona play but as Arsenal showed in the first leg, they are not invincible.
And while it may be a spectacular place to go and play a football match, the Camp Nou is not what you would call an intimidating stadium.
I have played and coached teams there and while it does take your breath away at first and there will be 90,000 fans there, most of them cheering on Barca, it is not one of the bear-pits of European football.
Those are the positives Arsenal can take into the second leg, but you don't need me to tell you what a tough job Arsene Wenger and his side have got on their hands.
In some ways - and this sounds strange to say - they might have been better off had the first leg ended 1-1, rather than 2-1. Now Barcelona know they have to go and win the game and that little change in mindset will make them an even tougher prospect.
I know they play to win every match but when you have that luxury of knowing a draw might be good enough, it can take that edge away; well, they don't have that any more.
To make matters worse for Arsene, he has a couple of major selection dilemmas, which is not what you want. Going to the Camp Nou with your strongest side is hard enough, but to go there without big, big players is another thing altogether.
Yes, getting Cesc Fabregas back is a huge lift to Arsenal, but losing Alex Song has left Wenger with a massive headache. I watched the Sunderland game and did think that neither Abou Diaby nor Denilson were that great, but I would be tempted to go with the former.
For me on Saturday he needed too many touches of the ball for an Arsenal player - they usually take two at most and shift the ball around - but maybe that was because it was his first game back after a while out. But, I still think Diaby should be the one that gets that holding role - and that will be so important because that back four is going to need some protection.
I would love to see Samir Nasri come in-field because I do think he has been their best player this season despite being on the fringes out on the left a lot of the time. But if you drop him into a three with Fabregas and Jack Wilshere, it is a little lightweight in the middle.
The absence of Robin van Persie would be a bigger blow though, because I do think Arsenal are going to have to score and as we saw in the first leg and in the Carling Cup final, he does give them that extra edge in front of goal, the ability to produce a special finish. He may be in the squad but I would be very surprised if they start with him and take the risk - as vital as he is.
I would bring Nicklas Bendtner in, just for that physical presence alone. Losing both Gerard Pique and Carles Puyol is a big, big blow for Barcelona, make no mistake about that.
We've seen how Manchester United fell apart without Rio Ferdinand and Nemanja Vidic and although Eric Abidal and Sergio Busquets are decent players and have played there before, let's be honest they are not the answer and Arsenal simply have to try and put those two under pressure.
Arsenal are never going to change the way they play though; they are not going to stop moving the ball round and go direct, so it will be up to Wenger to get the set-up right.
They have to try and squeeze Barcelona high up the field, move everybody up so the game is on top of that back four. Maxwell is the weak link and although he can be hit and miss, Andriy Arshavin can get in behind him down that right-hand side. That said, Theo Walcott's pace on the break, would have been a major asset away from home.
Squeezing up is a bit of a risk but if you look at Barcelona they do not have lightning pace, even in attack. Yes, their players are all fleet-footed, nimble and quick on the ball, but one-on-one that Arsenal back four would fancy themselves in a foot-race with David Villa, Pedro and even Lionel Messi.
That is never the problem with playing Barcelona though. The problem is their movement; it's making sure that when he makes the run off the ball, you are tracking their third man.
Dani Alves is a right-back, yet when the ball is on the opposite side of the pitch, in his own half, he will make that run forward which means he's either free, or someone has been pulled across to cover. The one thing that Arsenal midfield - and I include Arshavin and Nasri in that - is make sure they do not let people run off them.
They rode their luck at times in the first leg but I remember when they played Barcelona last season, they could've been 2-0 up in the second leg, so it works both ways.
Let's be honest, the one thing you need if you are going to get the better of Xavi, Andres Iniesta, Messi, Villa and the rest, you need to be lucky. You probably need them to have one of their off-nights as well.
And you need to believe. That, as much as team selection, is where Arsene Wenger will prove his worth in the second leg. He has to convince his players they are good enough to match them, playing the way they always play. You know they are always going to create chances and more times than not, you know Barcelona are going to score, so Arsenal just have to keep their minds focussed on the job. And they have to be lucky.
THOMMO'S VERDICT: If anyone is capable of going to the Camp Nou and taking Barca on at their own game, it's Arsenal, but I just think there are too many things working against them. They have a glimmer of hope with Puyol and Pique being out, but their own absentees might just prove too much to cope with. I think they will need to score and without van Persie, I'm afraid I can't see that happening here - and I can't see them keeping a clean sheet either. It is going to be a great game to watch I am sure, but I just can't see Arsene or Arsenal pulling this off, I'm afraid. I'll go 2-0 Barca.
Who will make it to the last eight of the UEFA Champions League?