As well as being able to revert to your favoured boots, being a free agent allows players to test out new boots, rivalled brand boots, that they wouldn't have been able to play in under contract. To find out what he'd been missing Alves, once of Nike's books, slipped into the Mercurial Vapor X for the clasico against Real Madrid. With the whole world watching it could have been interpreted as a shout to Nike that he's willing to come back.