If we're to have any chance of getting through this tie then we need to take a lead of some description to the Nou Camp. We need to stop being scared of what Barcelona can do to us and think what we can do to them. We've played some really good sides at the Etihad this season, and Bayern Munich aside, we've beaten them all, some of them fairly comprehensively. Barcelona are fantastic when it comes to possession, and attacking flair, but I don't rate them too highly when it comes to their defensive capabilities. Pique is a good player, but I don't believe he is suited to the "English game" and as such I think we can get at him, Alves and Alba are brilliant when it comes to attacking, but they're not the best defensively, and Mascherano is a fucking midfielder pretending to be a centre half, he's surely got to be someone we can get at. For the home leg I say we go with what's served us well for the rest of the season, 2 up top. People are putting too much importance on the Bayern game, that has to be looked at for sure but, for me, Bayern were exceptional that night, and we were terrible. Some of that was down to the tactics/formation, but some was also down to simply underperformance from us, and Bayern putting in what I believe even they say was possibly their best performance of the season. If we want to be the kind of side that is challenging for European honours then we need to be the kind of side that forces the opposition to respond to what we're doing, and not the kind of side that changes it's tactics due to a fear of what the opponent could do.
How we lineup in the Nou Camp will depend a great deal on what result we need from that game. If we have a lead then I'd go with just the 1 up top, play an additional midfidler and try to stifle Barca, if we need to get the victory on the night then I'd go 4-4-2 and play our normal game.