Juan Mata
Juan Mata has started four Premier League games this season. Getty

Jose Mourinho has opened up regarding his relationship with Juan Mata, and the difference between his importance for the current Manchester United project and the Portuguese manager's second spell at Chelsea. The Old Trafford boss also revealed it was the Spaniard who asked to leave during their time in West London.

Mata was named Chelsea's player of the season in 2011-12 and 2012-13, helping the Blues to consecutive Champions League and Europa League triumphs under Roberto Di Matteo and Rafa Benitez.

However, this was not enough to convince Mourinho of his worth following the return of "The Special One" to the club in the summer of 2013. The Portuguese boss preferred Oscar in the number 10 role and restricted Mata to just 11 Premier League starts in the 2013-14 campaign at Chelsea.

Mata accordingly moved to Manchester United in the January window for £37.1m. The Spaniard played a key role under both David Moyes and Louis van Gaal, but most expected his future at the Red Devils to be under threat following the appointment of Mourinho.

The arrival of Henrikh Mkhitaryan increased doubts further, as did him being brought on and substituted within the space of 30 minutes during the Community Shield victory over Leicester City.

However, Mata has since become a talisman for Mourinho. United have won all four Premier League games the player has started, losing the two matches he was dropped for: against Manchester City and Watford.

The Spaniard returned to the line-up for the match with Leicester City at the weekend, leading United to an impressive 4-1 victory as a number 10. He scored the second goal of the game before assisting Marcus Rashford for the third.

Jose Mourinho
Mourinho believes Mata has "found a very good natural habitat" at Manchester United. Getty Images

Mourinho has hailed Mata's contribution this season, suggesting he was not responsible for the player's departure from Chelsea in January 2014.

"I didn't sell him because my job is not to buy and sell," he said. "My job is to coach and my job is to work on the pitch. My job is to advise my boards on the transfer policy. I don't buy and I don't sell and I never did," Mourinho said in a press conference ahead of the Europe League game against Zorya Luhansk.

"Secondly he was the one who asked to leave and when a player asks to leave I think you always have to think twice. The third point is that my idea of football, with the squad I had at Chelsea, with the objectives we had at Chelsea is one thing. The football I want to play at Man United, the profile of my squad and what I want to do in this club is a completely different situation. My project at Chelsea he was a good player, my project at Manchester United is a very good player."

Mourinho also added that the style of his Manchester United has nothing to do with the way his Chelsea played on their way to the Premier League in the 2014-15 campaign.

"There are big differences," said Mourinho. "At Manchester United I have more players to play transitional football. Football is the main objective, we are not so physically strong and compact and playing in a defensive block like we did when we won the title [with Chelsea] in 2014-2015".

"The football we want to play here is different. We are in the beginning of that process. I think Mata is very adept to do that with his qualities. We need players with these qualities. He has found a very good natural habitat."