Mata, 25, was outstanding for Chelsea last term, scoring 19 goals and adding 35 assists as the club won the UEFA Europa League and finished third in the Premier League.

That form saw him take Chelsea's Player of the Year award, but speculation over Mata's future has raged after he was linked to Manchester United in a part-exchange deal for Wayne Rooney.

But Mourinho moved to quell further talk about Mata's future, praising his versatility and importance to Chelsea.

"Of course he fits into my plans," Mourinho said. "I have my idea about him, about where he produces better and where he has more difficulty.

"We will try to help him perform better in those situations. I've always liked a right-sided player to be left-footed.

"I started with (Arjen) Robben and (Damien) Duff, then (Goran) Pandev at Inter, and (Angel) Di Maria and (Mesut) Ozil. Many clubs do it. It's more than a tendency.

"I like wingers coming in on the inside for the penetrative movement, for the pass, for the shot. And Juan is the only player we have to do that on the right.

"On the left we have (Eden) Hazard, Victor Moses, Kevin De Bruyne, Andre Schurrle. Juan is also very comfortable playing as a number 10. In between these two positions, he has a lot to give to the team."

Chelsea begin their Premier League campaign with a home fixture against newly promoted Hull City on August 18.