2. Gerard Pique
Pique turned out to be one of the greatest defenders in the history of Barcelona, but he was a Manchester United player before his move to the Nou Camp. There were two players at the same stage of their career and Ferguson decided to stick with Evans and let Pique join his beloved Barcelona.
We all know how Pique developed at his boyhood club and how many laurels he has already won and will probably win for a couple of years more. Just think what he could have done had he remained at Manchester United.