Silva has played 30 EPL games this season , plus god known how many European / other cup games
I have to admit I was a little surprised that Rooney has clocked up 27 EPL appearances (subs for both are about equal with 2/3 each)
43 / 36 in total appearances this season, so while not a huge difference - this is probably one reason why Rooney looks fresher and still affecting the team positively while Silva looks exhausted.
Evra has played 30 League and 40 games in total (most other Utd players have been affected by injury /general rotation), and in some games this has shown to have an affect (whether its aging legs or SAF not trusting Fabio) but PE has been showing his age a little this season.
Yes and no, its too simple to put it in such terms both because, Silva had completely annonymous games early season. The Bayern game/tevez saga, Silva wasn't tired by then. Likewise Evra's utter crapness is both, from the start of the season, for the past two seasons and he's been LESS **** as the season has gone on, not worse(and that is largely the rest of the team playing better and allowing other teams less chance to attack).
Evra's poorness is his unwillingness to defend of late, most of the dodgy goals that were almost entirely his fault, say Arsenal against Utd, were because Evra is playing more as a left winger than a left back. He's constantly out of position, if it was tiredness he'd get forward less and he'd get worse as the season went on, neither of those things happen.
Back to Silva, again my belief is tiredness hasn't helped him, but its his actual ability at fault. He's never been a big game player and showed this in several big games this season well before you'd think he was tired. He's not a high goal scorer full stop.
He only got 4 goals and 7 assists in the league last year, and 8/7 for his last year for Valencia. People just got the odd idea this season that he's somehow be epic. I said it with Hernandez, and it happened to Silva and it could easily happen to Cisse/half a dozen other players, the league doesn't play against them, they aren't sure how they play the game and how to play against them. Half a season or a season later every defence knows to push high against Hernandez to catch him offside and know that if someone is wide and about to cross Hernandez is a danger man. Last season against Utd people probably played a deeper line and would look out for almost only Rooney.
experience against particular players makes a world of difference, Silva's game is fairly predictable, simple but, too predictable. Compare Silva to Fabregas/Xavi/Iniesta, he's slower, far less strong, far far less willing to run on the ball and far less willing to fight for it. Silva gets a ball and wants an easy pass, Fabregas/Xavi will happily burst a few yards, hold someone off, win the ball then make the simple pass, Silva simply won't 99% of the time.
People have simply crowded him out of games since xmas, while before they gave him space thinking getting to tight would leave them vunerable to him running past them. People have learned he mostly won't do that, so getting tight and he ends up passing back to midfield more often than not.
EDIT:- another important point is, not tiredness, but predictability. If every opposition manager/team knows Silva/Toure will play, then they can base an entire game plan around cutting those two out of the game, and then City become somewhat easy to contain. So over play someone, the team itself becomes more easy to assess tactically if you know what the opposition will bring each game, tiredness plays some factor, and teams also become lazy, if Silva is playing everyone always passes to Silva/Toure, so when one/both don't play, no one seems to know what to do. With Silva playing badly or not at all lately, there seems to be no plan to go from midfield to Aguero, there is no effective system for how they play, they just lump it long to Aguero and most of the time don't really support him.
You CAN'T play the same team every single game without problems settling in, most particularly with a fairly one dimensional lazy playmaker like Silva. With Xavi, Cabaye, Fabregas you can because they are massively more dynamic and unpredictable players.
