He was signed by Di Matteo from Lokomotiv Moscow and justified that faith with 15 goals in his first full season.
Odemwingie told The Sun: "We had some good times together and, when I got my first player of the month award, Roberto was manager of the month at the same time.
"I was sorry about what happened to him at Chelsea so soon after he had won the Champions League.
"We thought we could win. But it made it easier that they were not right.
"Maybe Roberto got the Chelsea job earlier than he expected and it was always a bit of a fight for him."