with the greatest respect Sharky, those players you named would probably be first teamer's anywhere else but Barca. Its a completely unique situation that they find themselves in there with that squad so i wouldn't go chucking those around as examples
IF O'Shea goes, that means we've lost Neville, Brown, O'Shea and brought in 1 lad, high potential but only 1 season of first team football, fighting for relegation. Now, you may say "but Brown and Neville didn't play" but thats not the point, they were there to be picked if the others needed a rest or if we picked up an injury crisis. They were an option. A squad game is all about options.
I hate to keep banging on about it, but O'Sheas experience is also invaluable, especially in a season where we've now confirmed departures of VDS, Neville, Hargreaves & Scholes, with potentially Brown to go out too. You need the older heads around just to calm the younger lads down when they start to progress in competitions.
Onto my last point, the twins are still growing and picking up a lot of injuries. Evra was pants last year and Evans was not great either. It would be prudent to keep O'Shea for at least one more season whilst everyone settles in.
Especially in a season where we will be bedding in a new GK!