Meanwhile, Mark Bosnich is challenging Ferguson to repeat his criticisms of him to his face.
The former United keeper is described as a “terrible professional” in Fergie’s new autobiography.
The Scot is set to visit Australia later this year to watch the Melbourne Cup and Bosnich, who lives in Sydney, wants a showdown.
Bosnich said: “I’ll definitely go down there if he is down there and ask to see him and if he doesn’t want to see me that’s fine, but then I will have the right to my reply.
“I’m going to tell him straight to his face and I’ll ask him to repeat his criticism then I will tell him exactly what I want to say and you guys can all read about it, like you read his book.”
Ferguson criticised Bosnich’s weight, saying: “We played down at Wimbledon and he was tucking into everything: Sandwiches, soup, steaks. He was going through the menu, eating like a horse.”