Clattenburg and many rival managers, including Ferguson, were shocked by Chelsea's accusation that he used racist langauge towards Mikel last weekend.

"It's a free country where everybody has freedom of speech. We take into consideration what other people say and use it as a motivational tool for ourselves. It is a free country, as I say, and everybody can say what they want. He [Ferguson] likes to talk about other clubs; we tend not to. I'll leave it up to him," the Italian said.