Simply trying to pass the ball into the net will not yield any results. We witnessed Barcelona's possession style of football thwarted by both Real Madrid and Chelsea. While the former has ended all hopes of La Liga glory for the Blaugrana, the latter seek to exact vengeance and cement their place in the final of the 2012 UEFA Champions League.
Chelsea are obviously in the driver's seat, having won the first leg without conceding any goals. A lone goal from Chelsea in the second leg may be enough to send them through, as Barcelona would have to score at least three—a task much easier said than done.
Furthermore, Chelsea rested eight of their key personnel in the game against Arsenal—besides Gary Cahill, John Terry and Petr Cech, all the other players that started against Barca were rested.
However, Chelsea should not try to simply "park the bus," as Barcelona will figure out a way to compete.
After the first game, I was thinking of what kind of formation might offer Chelsea a tactical advantage in the second leg, and I thought that a 4–4–3 formation with Didier Drogba, Fernando Torres and Ramires with Juan Mata playing centrally might be best.
But, after witnessing Torres' performance against Arsenal, I think a 4–5–1 formation might work well for Chelsea.
Here's picking a Starting XI to put Chelsea through to the finals.