For football reasons
Mata was very much a fan favourite at Stamford Bridge after his move from Spanish side Valencia, winning Player of the Year in two consecutive seasons for the Blues where he won an FA Cup, Champions League and Europa League in his first two seasons.
However, things changed when Mourinho made his return to club as game time dried up which eventually paved the way for his big money move to Old Trafford in January 2014.
There was some concerns about the Spaniard's future when Mourinho moved this summer, however Mata has become a key player in his side and he stated that his move from Chelsea was for football reasons.
"Sometimes in life and in football as well," Mata told the Premier League Show. "Change comes and you have to embrace it."
"When Jose came I was not playing a lot," he admitted to host Gary Lineker. "I had the chance to go to another great club and it was a good offer for Chelsea as well so that’s how it worked."
'No, (there was no fall out)," he admitted to the BBC programme. "No I think it was a football reason or a style or something like that but we never had a personal problem."
"We are working together now," Mata added. "It’s going fine."
Expectations are high
When he made the £37million move from Stamford Bridge back in 2014, Mata easily became United's most expensive player ever but that has been eclipsed in the subsequent years.
The club and the world record transfer now belongs to former midfielder Paul Pogba, who made his record-breaking return to North West last summer.
The Frenchman has come under his fair share of criticism since making his return, but Mata stated that it is a lot pressure to have such a transfer fee hanging over you.
"I imagine it’s not easy," said Mata. "These big transfers come and the expectation is so high."