He's definitely past it I'd say, he really has declined quickly. Maybe he should finish his career after this season, to at least keep some dignity.
If you are saying that please go and see the Villareal game in which Xavi was subbed on he changed the whole game in Barca's favor and single handed dismantled their midfield. He can't play 3 games a week and no one expects him to do so but when rested properly he is still one of the best holding midfielders in the world