Chelsea's smiling assassin 'Johnny Kills' AKA Juan Mata remains positive despite club's managerial merry-go-round

Chelsea playmaker Juan Mata says the sacking of two managers in the 18 months since he arrived at Stamford Bridge has not wiped the smile off his face.

In an exclusive chat with ITV ahead of the Blues' FA Cup Sixth Round match against Manchester United at Old Trafford, Mata explained his motivation to win more trophies, despite having already pocketed the European Championship, World Cup and Champions League at just 24 years old.

"I'm hungry, and my motivation is waking up every day and coming to training with my best smile," Mata told ITV's Gabriel Clarke.

"Though you can have good and bad results, you have to be always in a positive way."

And the Spanish international said the chopping and changing by owner Roman Abramovich has no impact on his professional approach.

"We've had three managers, three of them great people I have to say, and we have to be professional and play at our best level whoever the manager."