From The Daily Mail:
"I had agreed to do the book. I still believe I was 100% right about the World Cup.
The surgery was something I needed to have done and the sending off? Well, Jason McAteer would annoy anyone. He‘s had a great season hasn‘t he."
Defending the controversial content of his book, Keane went on: "I could have left bits out, the drinking stories, getting into trouble, the crazy things, the stupid things, but I would have felt guilty.
"Too many books have bored me to tears. You don't have to give every detail, but I wanted to offer some insight into what football is really about."
The Old Trafford tyro also acknowledged that the injury problems which prompted his retirement from international football were likely to affect him for the rest of his life.
"There's no doubt I'm doing myself damage, the surgeon will tell you that. But I could be hit by a bus tomorrow and that would be that anyway.
"There's going to be a downside to it, especially when you've had injuries, but I know big Paul McGrath and I see how he struggles with his knees. He'll tell you he wouldn't change anything.
"If I have to limp around I'll get a walking stick, and my wife has said she'll push me around if I need a wheelchair."