Guess you haven't read his autobiography either, then. Some journalist has!

Quote Originally Posted by a bunch of sites
Ferguson is a long-standing admirer of the France midfielder and is thought to rate him among the best of a series of possible replacements for Roy Keane. Ferguson said last season that he missed the opportunity to sign Vieira before the player's move to Italy last summer. 'We'd been down that road so many times, where we'd been told he wanted to sign for United and then ended up staying at Arsenal. So I dismissed it, and then it became a reality when he left Highbury for Juventus. Whether Arsenal would have sold him to us is another matter.'

Vieira, also a target for Roma and Internazionale, revealed in his autobiography last year that he would contemplate joining United, despite his numerous run-ins during matches against the club, notably with Van Nistelrooy. 'When you are a player, you always look at the best,' he said. 'And that Manchester United team was the best in the country.'