Mourinho has left Mata on the fringes of his Premier League squad this season and has encouraged the Spaniard to raise his game – particularly when he does not have the ball - if he wanted to be included.
Mata has made just two top-flight appearances this season for Chelsea, and was left out of the squad altogether in their 2-0 win over Fulham last week.
But the 25-year-old was given a full 90 minutes in Tuesday's 2-0 League Cup victory over Swindon Town, and impressed, with Mourinho expecting more of the same if he features against Tottenham on Saturday.
"I liked the way Juan Mata played against Swindon," he said. "His attitude is very good and his effort was good.
"When a player makes an effort to come in my direction then I go to him as well.
"I can imagine from now, him working into my way of thinking and I think the natural tendency will for him to be in the team."
Mourinho was reluctant to discuss his fractured relationship with Tottenham manager Andre Villas-Boas, but did reveal he would have a post-match drink with his former scout if it was offered to him.
Villas-Boas formerly worked under Mourinho at Porto, Chelsea and Inter but was denied a more senior role and decided to leave.
"I don't discuss this (their relationship) with the media, it's a personal thing," he added.
"I don't care what he says. I'm not here to do that. I'm not interested.
"I managed a Champions League final against a manager who was important in my career and taught me to grow up and I did it in a professional way. And that is a way you have to do it.
"I have had so many assistants in my career. I was always an open book to them and with the coaches in the academy. Will I go for a glass of wine with him? When people invite me I always go. I never refuse.
"But I have nothing more to say on this."
Mourinho also revealed that midfielder Ramires was a doubt for Saturday's encounter at White Hart Lane after being substituted at half-time - having come off the bench himself - with a hip injury against Swindon.
