Di Matteo remains on course to mastermind a fairytale end to the Blues' season - despite Wednesday night's crushing Barclays Premier League defeat to Newcastle, which all but ended their top four hopes.
That was the the Italian's first major setback since he became caretaker boss exactly two months ago, since when he has led the club to both the Champions League and FA Cup finals.
It remains to be seen whether winning one or both will be enough to convince Chelsea owner Roman Abramovich to hand him the reins full-time.
But Terry had nothing but but praise for the job his former team-mate had done going into Saturday's showpiece at Wembley.
He said: "It's funny actually, because me and Robbie shared a little joke about this and he would never have envisaged me going on to captain Chelsea and going on to do what I've done in the game.
"And the same with him as a manager, and him being my manager and being at the business end of the season in big competitions.
"We're very passionate about the club. He cares for the club immensely, which is great, and that's certainly rubbed off on the players.
"So he's been a revelation, really, since he took over.
"He shows that he cares and the passion shows in the team meetings and on the training field when things don't go well.
"He always refers back to the way he cares about this football club, the relationship he has with the fans as well.
"He's got a great rapport with the fans, a great understanding with the players.
"He's communicating with everyone and things have gone very well for us.
"So he deserves a huge amount of credit for that."
Chelsea looked set for their worst ever season since Abramovich bought the club under the doomed stewardship of Andre Villas-Boas.
But Di Matteo has somehow managed to pick up the pieces, despite a punishing schedule that has seen them play at least twice a week for the past two months.
Terry told Chelsea TV: "We've had so many games.
"It's been training and playing every two or three days.
"He (Di Matteo) just kept everyone fresh in the mind that they can get a chance and the opportunity.
"Then, once you do get that opportunity, if you do well, you will stay in the side and progress and keep your starting place, which everyone throughout the side has felt."