In all honesty, how many 31 year old midfielders have made it in to the England squad since 1990.

Gazza wouldn't have made the 1998 world cup squad because he was past it. He was probably past it 1996, but Venables gave him his last chance. His fitness was irrelevant. Anyway, define off the rails. Gazza went "off the rails" as you put it, because of events that occurred on the pitch rather than off it. I don't think Gazza is an exception at all. His portrayal through the hyper-reality presented to us by the media makes us believe he is an exception, when in reality his ability was hyped over in much the same way as Rooney's is now.