If Ferrara believes we are more than half way through to the semi finals then he may play something like this:
Manninger
Zebina Legro Cannavaro Molinaro
Melo
Marchisio Tiago
Diego
Trezeguet Giovinco
By playing this way, he gives a resting time to Del Piero, Iaquinta, Amauri, Zanetti, Chiellini and Grygera. In addition he will be giving more players a chance.
That is said, I don't think he will do A MAJOR CHANGE but we will see changes.