Di Matteo's near eight months in charge of the Blues have been arguably the most turbulent in their history but he has somehow managed unprecendented success while at the helm.
Having ended Chelsea's agonising wait for Champions League glory, Di Matteo has led them to a four-point lead at the top of the Barclays Premier League and transformed them into one of the great entertainers of the game.
His success is all the more remarkable considering he took charge of a dispirited squad, which was on course to record the club's worst season of the Roman Abramovich era, and has since had to contend with the fallout from the John Terry racism scandal.
Chelsea managers have crumbled under far less pressure than that which has been piled on Di Matteo.
And Mata, who has been the club's star of the season and arguably the best player in England on current form, could not praise the former Stamford Bridge midfielder highly enough.
He said: "Robbie knows very well the team, Robbie knows very well the club as well. 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."
Chelsea are not short of "legends" in the current squad, with Frank Lampard, Petr Cech and even Terry firmly in that category.
Mata may be only in his second season at Stamford Bridge but he will surely join those ranks if he maintains the kind of form that has seen him score six goals - and set up many more - in his last five games.
"We have three or four players who are very, very important for us," Mata said.
"They are legends now at the club because of what they did during eight, nine, 10 years.
"And they are our captains as well, so they are the present and still the future of Chelsea.
"On the other hand, we have young players, for example like me, who want to be as good as them in the history of Chelsea.
"I wish I will be like Frank Lampard or like John Terry in the next years.
"This is my second year at Chelsea. I really enjoyed the first one.
"It was one of the best in the history of Chelsea.
"But I think the best is still to come, hopefully.
"We are now enjoying (life) with young and with experienced players and I think there is a balance that we have in the dressing room."
That balance will be offset slightly while Terry serves a four-match domestic ban but he will be back for tomorrow night's crunch Champions League Group E clash at Shakhtar Donetsk.
The 31-year-old will captain the side after Chelsea controversially refused to strip him of the honour over the language he used towards Anton Ferdinand a year ago tomorrow [Tuesday].
And in timing that could hardly be more ironic, the defender will also wear an armband bearing the slogan 'Unite Against Racism' as part of a Football Against Racism in Europe (FARE) campaign scheduled for this week.
If Terry has shown the unacceptable face of Chelsea, Mata has been the complete opposite but he was modest today when it was suggested he was the "face" of Di Matteo's new-look side.
The Spaniard was more interested in how the Blues were performing as a team than his own individual exploits and predicted a "fight for the ball" in tomorrow's [Tuesday] match against a Shakhtar side who are in even better form.
He added: "We're going to try to play our football, as we did the last two months, enjoying ourselves, enjoying the team, enjoying the level that we're playing with and that's what we want for tomorrow [Tuesday]."