Mata describes Di Matteo as a Blues legend.
He told Absolute Radio: "I think when youâ€™re a manager you play or the way that you play, is because of the players that you have. This year we have more midfielders, more quality players, and we are playing different from the last year.
"But I think because of the new signings, talking about manager Di Matteo he is a very, very good manager, heâ€™s so clever, he knows very well how is playing and managing for Chelsea. He used to be a legend here. So itâ€™s very important for us to have a manager like him."
Mata was speaking to Ian Wright of Absolute Radio Rock n' Roll Football. Saturday's from 5pm on 1215AM. For more, visit absoluteradio.co.uk/football