I think it would be weird to see Tevez go, and, oddly, I don't think we ever seen the best of him. I was reading a quote a few weeks back (I can't remember who by) which was basically saying England has ruined Tevez, which I sort of agreed with. He works harder than he really should, he probably doesn't show as much ability as he has and I think the emphasis on work rate over here can have a negative effect on players. I remember Tevez at United where it seemed he was played mostly for his work rate, although he had a successful season there, he probably never shown them what he was truly capable of. Similarly at City, he's worked his nuts off when playing, but the player that left South America has changed massively, and I'm not too sure if I really like it.
Another player that you could say this about is Torres. When he came to England, he worked hard, but he was a massive threat with the ball at his feet for such a powerful player. Since then, it felt more like Torres was running after the ball instead of with it, which I feel has changed his game negatively. If you look at Torres in the national side, he looks out of place because he isn't as comfortable on the ball as the others, but he wasn't always like that, not IMO anyway, it was never 'his game', but at the same time, I feel he became more limited in his time here, and relied more on chasing down defenders instead of beating them.
I dunno, it's an interesting way to look at things, but I even think Rooney changed for worse during the years before last. The emphasis was always on his work rate, but he had a lot more than that. He still does, no doubt, but I think some of his 'natural game' has been taken away/sacrificed to emphasise on his work rate. Less so since he was played behind Hernandez, where it seemed he was able to play a more natural game, but for long spells areas of his game weren't utilised. The opposite of this example could probably be Dimitar Berbatov who, if he worked harder/shown a bit more aggression, would probably be amongst the top 5 forwards in the world.
I'm intrigued to see how a player like Luis Suarez develops in his time here. There's no doubting he works hard, but will this side of his game continually be pushed at the sacrifice of his ability? I hope not.