It is not just during the season when the football world can shock, stun and amaze. Each summer, the transfer window generates dozens of fascinating sagas as teams look to strengthen and players look to cement their legacy (and/or earn themselves jaw dropping wages). Sometimes these transfers seem to come out of thin air, whilst there have also been several players that have done the unthinkable and joined their clubs fiercest rival, much to the fans dismay. These unbelievable transfers are the ones that shake the entire football world and the ramifications from many of these are still felt today.
10. Carlos Tevez (Man United to Man City)
Despite impressing and playing an important role at United, ongoing contract issues and growing tension between Tevez and Sir Alex Ferguson ultimately saw him make a move away from the club in 2009. Tevez ruled out moving to Liverpool due to their rivalry with United, but he instead moved to their cross town rivals Manchester City for a British transfer record of around £47 million. Manchester City were very much on the rise and a threat to Manchester United, and Tevez became the first player to switch between the clubs since Terry Cooke in 1999. Tevez would help Man City to the Premier League title in 2011/12, but that season was shrouded in controversy after Tevez refused to come on as a substitute against Bayern Munich. He moved on to Juventus in 2013 and has recently returned to his first club, Boca Juniors.
http://man-news.com/carlos-tevez-transfer-news-west-ham-beckons-031611718 Source: Man-News.com