TheNearPostSpain are lacking in directness and width. This lineup gives them some of both, but retains most of their passing midfielders. It's supposed to go from a 4-1-4-1/4-3-3 shape to a 4-1-3-2 looking shape. Iniesta defends centrally but can drift to the left when Spain have the ball. Pedro can occupy the opponents right full back, right center back, or split the channel between the two. Navas provides pure width, running up and down that flank, which is useful considering Arbeloa isn't that great on the overlap.
On that note, it might be worthwhile to move Busquets to centerback and play Sergio Ramos as the right full back. That gives Spain more attacking options, and a calm passer in the back.
nvrDespite all his ups and downs I'd start Torres over Llorente. He has heaps of experience in big tournaments. His current form is pretty good too.
TheNearPostThat's also a very possible lineup. Gives Spain width (Pedro), somebody between lines ( Silva), and driving runs from midfield ( Iniesta).
G.K.JG has nailed it.