The Old Lady will face Chelsea in the Champions League and the first leg will be played at Stamford Bridge on Wednesday.
Ranieri was sacked after just one season under Abramovich in 2004 after an impressive season.
“When Kenyon came, I was frozen,” he said in the Daily Star Sunday.
“Kenyon was the new boss and new bosses tend to want to bring in their own people.
“I was not one of his people.
“Am I bitter? Yes. Bitterness, rancour, hurt – call it what you like.
“Before Abramovich came, I was doing my job. I carried on doing it for him and I wanted to continue doing it.
“In the end, after a game against Leeds, I knew the players and the supporters were with me even if the club was not. They knew I had left a legacy.”
He added: “We will try to stop Chelsea reaching the top of the world, which is where Abramovich has programmed them to arrive.
“I don’t think they will be happy about facing us.”