Di Matteo lost his job after Chelsea's Champions League defeat to Juve.
"Roberto is a valid coach, won the Champions League in London after many years of trying, I feel sorry for his dismissal," former Middlesbrough striker Ravanelli told TMW.
"I know him and he is a great guy. Apart from the game last night, where the team did not play as it should and found in front of them a great Juventus, he has done very well.
"I wish him great luck for the future."