The Blues boss has explained why he left the Spain international out of the squad to face Fulham and was delighted with his side's 2-0 victory at Stamford Bridge
The Portuguese left Mata out of the squad for the Blues’ Premier League match against Fulham, with Oscar and John Obi Mikel scoring in a 2-0 win.
Mourinho reiterated his desire for the Spain international to adapt his game and explained why he had not been included in the match-day squad.
"As a number 10 he [Oscar] gives us creativity and he gives us ability to press up and defend," he told Sky Sports.
"Juan has to learn to play the way I want to play. He has to be more consistent, he has to be more participative when the team lose possession.
"I think it is not his fault, just the way he has played in recent years."
The result sees Mourinho’s men bounce back from a disappointing seven days, which included defeats to Everton and Basel, and he was happy to return to winning ways.
"Against Everton we went home very, very sad and today we go home very, very happy,” he added.
"The result was better than the result against Everton. I still think that we played much better against Everton than we did today but points are also important.
"After a bad start, a start that everybody kept telling me is the worst start for about a decade [for Chelsea]…today I looked at the table, nobody is in front of us.
"The beauty of the Premier League is that everybody loses matches and everybody drops points. The top six teams have already had a defeat, so no dramas.
"I am aware we are not playing very well but we will work, we are top professionals and everybody is working hard."