#4 Mats Hummels
Mats Hummels, despite being one of Borussia Dortmund's most popular and consistent players in the last few seasons, started his career with the Bundesliga giants and bitter rivals Bayern Munich. He started in their youth academy in 1995 and appeared for the Bavarian B team and first team before he moved to Dortmund permanently in 2009. After spending about 8 years with them, he expressed his desire to go back to his former club at the end of the 2015-16 season.
His move to Bayern Munich was made official at the end of May ahead of Euro 2016 on a five-year contract. In spite of providing years of faithful service to BVB, fans of the club were very hostile towards him for changing allegiances. He was whistled at by fans of the Westphalians – a reaction which took the defender by surprise. He had expected fans to be more understanding after giving them 8 years of his career.