9. Juan Mata (Chelsea and Man United)
Chelsea signed this Spanish magician from Valencia for £23 million in the summer of 2011, under then boss Andre Villas-Boas. After scoring on his debut versus Norwich, Mata scored won the club’s Player of the Year Award in the two consecutive seasons he was at the London club. He also was part of the Champions League winning squad against Bayern Munich in May 2012 and also added the Europe League to his collection of trophies the following year.
However, to everyone’s surprise, when Jose Mourinho returned to the club, he didn’t include Mata in his plans for the future even after two unbelievably successful seasons for the Blues. This led to his transfer to rivals Manchester United in 2013, where he has scored 16 league goals.