Roy Keane's biographer has criticised his management at Sunderland.

Eamonn Dunphy has joined the debate on Keane's ability as a manager and whether he will survive the club's worst run since he took over in summer 2006.

And the former Ireland international, now an outspoken pundit on Irish television, is convinced Keane will walk.

Dunphy said: "It has been apparent for me for the last 18 months that he isn't going to be a serious manager.

"If you look at the players he has brought, in and out, it is remarkable, staggering and he has wasted a lot of money. He doesn't appear to be cut out for management like a lot of great players.

"He is very intelligent, a great player but look at the likes of Bobby Charlton and Bryan Robson. They were great United players who didn't make it as managers.

"Management is very different these days in the Premier League. He had a great start but maybe getting promotion in that first season wasn't such a great thing. I don't think the club were geared up for the Premier League, not just financially but you need the scouting systems too. I just don't think Roy has the qualities. It is becoming apparent.

"He hasn't had a settled side and I think he is in a fog at the moment. Everyone gets there at some point in your life, when things get too much for you.

"You don't know where the levers for control are and he's making some really silly decisions. He paid all that money for Anton Ferdinand and dropped him. Diouf on the bench, out of favour." He added: "He is rambling about all sorts of things and it's really ridiculous. I think Roy Keane is beginning to believe the Roy Keane mythology. He is pontificating on everything and he's lost the plot.

'I have the highest regard for him. He is a remarkable man, intelligent, highly calculated, family man and he is a very shrewd guy. The idea that he is a headbanger or that he is impulsive is wrong but he has lost the plot, big time. He wants to win and he is in serious danger of getting relegated.

"If he leaves, he will leave to the best affect for himself. He won't want to be humiliated. He is not a quitter, there is a new owner and the goalposts have moved.

"I think the whole project is doomed. Maybe he needed to start, like Clough or Shankly, down in the lower leagues and learn the business of management and all its aspects. If you go in too quick you are struggling.

"I think it takes two or three years to learn about how to deal with directors, how to operate in the transfer market, set up scouting systems. I don't think Roy had the chance to learn the business of management."