Silva is at his best when he can run in the space between the midfield and defence, and there's very few players in the world who are as threatening as him at picking out a brilliant pass. Even today he created some great chances that were wasted. The problem is that we don't often see Silva in this area much any more, because the way we change from defence to attack is so slow. In the first half today every time we won the ball back in our own half, we either gave it away quickly or passed it back to Hart who would inevitably give away possession.
We've had this problem for a while now, and I believe it's why Mancini opts to play Yaya further back, as he's the only midfield player who has the ability to pick the ball up, hold off any pressure, and play the ball to one of our players. Unfortunately, Touré doesn't do enough work defensively, so we can often get overrun in midfield when another team tries to pressure us high up the pitch (like Dortmund or even Liverpool recently).
Really, I believe we need more technically sound central midfielders who can help us dominate and control the game, and perhaps more wide, faster players who would often run in behind or just generally help to generate space for the rest of our team. At the moment when a team pressures us, we don't have the passing or movement that is required to escape through the pressure, and until we fix that we will always struggle away from home and against other top teams. Silva would be brilliant if he had them type of players around him, as he is for Spain and would be for a team like Barcelona.