The Italian has worked wonders with the Blues since taking over from Andre Villas-Boas last year, guiding the club to the Champions League/FA Cup double, and having them sit four points clear on top of the Premier League table this term.
Mata, who is in devastating form with six goals in his past five appearances, is loving life under Di Matteo who he thinks is a great fit for the Southwest Londoners.
"Robbie knows very well the team, Robbie knows very well the club as well," said Mata. "He is a legend here.
"And now, as a manager, he connects very well with the team, in every meeting, in every speech, he does deep inside every one of us, talking about every game.
"I think it's very important to be ready for every competition, for the Premier League and now for the Champions League.
"He knows how important it is for the club to play these kinds of games, to win again the Champions League like last season.
"So, I think for us, he's the perfect manager."