Chelsea players last weekend.
But the United manager is not convinced that Clattenburg is capable of making such comments and that he doesn’t believe Chelsea’s accusations.
He told Sky Sports: “I don’t believe Clattenburg would make any comments like that. I refuse to believe it. I think it is unthinkable.
“In this modern climate I just don’t believe it. Simple as that. There is no way a referee would stoop to that level, I am convinced of that.”
Ferguson went on to admit that the game has changed dramatically over the past 20 years but he admits that he has never heard any reports that referees had used bad language on the pitch.
“I think the modern game we see today to the one we had 20 years ago has completely changed,” he added.
“I played myself and I know that the banter goes on between referees and players. Twenty five years ago it was different from today.
“I have never heard of player coming to me in the last 15 years saying the referee has sworn in a game. Ever. So that is where I stand. I don’t believe it.”