you're either 14 or never played football before. the way barcelona plays wingers they are pretty much all strikers, in and out of position. So I guess "striker" means that you have to sit infront of the net the entire game hmm? Nah, get a clue. Villa is all over the field and attacks from the wings consistently every single game. He has the experience and skill to easily play as a "left winger", meaning he merely starts at the left but can easily flow and rotate with Ibra AND Messi. Quite funny how b/c wikipedia tells you this is said guys position, you automatically neglect the idea of him being able to do anything else. Good job.
Edit: Henry was 31 years old last season and a "center" striker his entire career until he moved to Barcelona. Yet he scored 20 goals last season. What makes you think Villa or Rooney couldn't do the same? Who do you actually want as a LW replacement? Ribery etc? He isn't exactly known for his goal-scoring prowess, neither is Silva or a few other natural winger targets.