Chelsea boss Roberto Di Matteo has responded angrily to comments made by Manchester United manager Sir Alex Ferguson yesterday, as reported by the Daily Mail.

Ferguson claimed it was poor that Chelsea had sunk to accusing the referee of ‘inappropriate comments’ after their game last Sunday, but Di Matteo wasn’t happy with the United boss once again talking about him, Chelsea and their business.

“He likes to talk about other clubs. We tend not to. I'll leave it up to him,” Di Matteo told the Daily Mail.

“It's a free country where everybody has the freedom of speech. We'll take into consideration what other people say and use it as a motivational tool for ourselves.

“The investigation will qualify this. We don't want to prejudice any trial.”

When asked if he felt Chelsea may now be targeted by referees, Di Matteo said: “I really hope not. I believe that they won't. We have faith in the referees. They are people that are under a lot of pressure.

“They are human beings like everyone else. You have to try your best and sometimes mistakes can happen.