Chelsea fans were delighted when José Mourinho returned to the Stamford Bridge dugout in 2013, but eyebrows were raised at his decision to freeze out midfielder Juan Mata.
The Spaniard had been Chelsea's Player of the Season in both the 2011/12 and 2012/13 campaigns, but Mourinho chose to move the Blues in a different direction; controversially selling the Spaniard to Manchester United for £37.1m in January 2014.
It sparked all sorts of rumours of a potential bust-up between the pair, but Mata sat down with adidas & 90min, celebrating the release of the new X Ghosted boot in a fresh podcast series, to set the record straight.
"At the time, it was a bit difficult because [things were great in] 2011/12 and then the next season, which probably was my best season in terms of numbers and games played and enjoying on the pitch, 2012/13," Mata remembers.
"We won the Europa League at the end with Rafa Benítez as a coach and everything was going so well on a personal level. And then José arrived and he had a different way of playing football, or a way that was not perfect for my qualities as a player, and that was it. I was not playing much as I used to play before.
"There was never a personal problem between us, like some people said at the time, but it was a challenge for me. Having been Player of the Season for the last two years in a row, playing nearly 70 games [in 2012/13] and feeling like an important player of the group, everything changed and I had to prove myself again. I didn't last very long after that at Chelsea."
Not only did Mata have to try and win over Mourinho once, but he had the unenviable challenge of needing to do it twice. Just two years after his move to Old Trafford, Mata was joined in Manchester by Mourinho, who was looking to rebuild his reputation after a disastrous final year at Stamford Bridge.
The rumour mill began churning once more in Mourinho's first game in charge, the 2016 Community Shield, when the boss brought Mata on as a half-time substitute and withdrew him in injury time. The reports of tension between the two were back but were quickly proven wrong.
"I always tried to adapt," Mata says. "I could see that, when he came to Manchester United at a different stage of my career, everyone was saying 'okay you have no future at the club, you're going to have to leave, whatever'. I was calm with myself.
"I know what I am as a player. I know my will to adapt, and I'm proud that time proved me right as I felt an important player at Manchester United. What I try to focus on is things I can control: my attitude, my qualities as a player, keeping my confidence high, keeping my physical state high, and that's it."
Mata did manage to prove Mourinho wrong, playing a key role in the Red Devils run to Europa League glory in 2016/17.
"It meant a lot to me," he says of that triumph. "Yeah, he was the same manager, but sometimes the squad is different, the quality of the players is different so he has to play a different way. We know from one month to another, a lot can change in football.
"It meant a lot for me to feel like an important player and to play in those finals with him as a manager."
Facing pressure is nothing new to Mata. He had to combine his struggle to win over Mourinho with the day-to-day pressure of life as a United player - something Mata admits became clear to him as soon as he set foot in Manchester.
"Well, it's not easy to manage the responsibility of playing for Manchester United," Mata adds. "After every single game, every single day, there's news about Manchester United. Signing players, whatever happened in the game - the expectations are incredibly high.
"Since the first moment I arrived in the helicopter, in my presentation, I felt the size of the club, the structure of the club, and every day when I go to training or to play, I feel privileged and lucky to say that I am a Manchester United player. I feel proud.
"Sometimes it's difficult to stop and think where I am, where I come from and everything I have achieved in my career. Thinking about the kid that was playing in Oviedo with his friends, now I'm playing at Old Trafford every week."
The adidas X podcast is available on audio platforms to download and listen here:https://podfollow.com/adidas-x/view.