1) Juan Mata
Mata joined Chelsea in 2011. He spent three years at Stamford Bridge but failed to nail a spot in the starting line-up in his last season with Chelsea, under Jose Mourinho.
The skilful Spanish midfielder is highly regarded for his ability to pass accurately and control the ball well. The lack of game-time forced Mata into a move away from the London club and he has now become a regular player for the Red Devils.
At 29 years of age, Mata continues to play beautiful football for his team. His great vision of the game has allowed him to contribute to the attacking force of his club.
At times, Chelsea players lack that creativity and imagination to spark an attack. Mata's presence allows the team to be less stagnant and it is regrettable that Chelsea sold him to a fierce rival.