The assassination of Sir Alex Ferguson’s character has been brutal in its execution, Roy Keane performing for the television cameras in a manner that must have even had his ghost-writer Roddy Doyle wondering if he could have drawn more of that anger from his subject.

The words fly like verbal bullets towards their target. Ferguson’s ‘statue’; the ‘millions’ he has made on the back of players whom, in Keane’s view, he has now betrayed. If Carlsberg did book launches.

But away from the many microphones, in a private room at the Aviva Stadium, Keane is now offered the opportunity to reflect in more detail on the breakdown of a special relationship he once enjoyed with his former manager.

VIDEO Scroll down to watch Roy Keane say he may never forgive Sir Alex Ferguson

Sir Alex Ferguson and Roy Keane celebrate in the dressing room after winning an FA Cup semi-final match against Arsenal in April 2004

Ferguson and his then-captain Keane's departure from Manchester United in 2005

Keane is now assistant boss at Aston Villa and the Republic of Ireland

I suggest it is a little sad that it has ended in such bitter divorce. ‘I don’t,’ he quickly replies. ‘Why is it sad? Did you think we were going to be pals? Did you speak to Bryan Robson? Did you ever speak to Steve Bruce? Did you ever speak privately to them when they left? Do you think it was a pals’ act for them?

‘I knew what was coming. Brucie at the cup final. Robbo at the Cup final. Speak to their wives about what happened to them at the end of their careers.

‘So I don’t think I ever thought it would be any different because that’s what happens with him. Do you think Ruud van Nistelrooy left well? Do you think Becks left well? To be fair, Becks and Ruud did have moves lined up. But I didn’t. I was leaving with a broken foot.’

There are two sides to every story and the publication of two books, first Ferguson’s last year and now The Second Half by Keane, has given us the opportunity to draw our own conclusions. In the view of this observer, Keane’s grievances are more justified.

But as manager and captain they were a formidable team, with a mutual respect unique to that particular United dressing room. Keane was seen as an extension of his manager on the pitch.

Does Keane think Ferguson will regret the way things have turned out? Does he believe, even now, that Ferguson would take some pleasure in seeing a former player like Keane do well? Keane thinks I’m naive even to float such an idea. ‘Do me a favour,’ he says of a man he never once refers to as ‘Sir’ in the book.

‘Not a chance. He doesn’t work that way. If Darren [Ferguson’s son] is doing well, that’s all that matters. If anything, he doesn’t want people to do well. Brucie, Robbo. Ask them about loan players. Do you think he did them favours? Brucie got more favours off Arsene Wenger.’

Keane and Sir Alex on the Old Trafford touchline as opposition managers in 2007

Keane lifts the Champions League after Manchester United won the final in Barcelona in 1999

Keane is watched by Ferguson in a training session at Carrington training ground in 2003

Ferguson talks to David Beckham on the touchline during a Premier League game vs Newcastle in 2001

Ferguson greets Ruud van Nistelrooy during a 3-1 away win at Charlton in the Premier League in 2005

Ferguson walks up the touchline with former player and then Birmingham manager Steve Bruce in 2004

Ferguson fits former Manchester United legend and captain Bryan Robson for a shirt

In the same position, would Keane be more generous? ‘I hope so,’ he says. ‘Although it wouldn’t be hard.’

He said he was being generous when he raised his concerns about the controversy over racehorse Rock Of Gibraltar with Ferguson all those years ago. Foremost in his mind was the impact a dispute between the manager and the club’s Irish owners might have on team performances. But he was also worried it might not end well for a boss he cared about back then.

‘I brought it up in a friendly way,’ he says. ‘I was in to see about my last book. I think I’d given him a chapter or something like that. And I said, “Oh by the way, I’ve been told you are not going to win this”. But he said, “Nobody does that to me” and all that. And I said, “OK, go ahead”. I was just trying to be friendly with him. I was warning him that these were serious people, which he obviously later found out.’

Keane saw it as an unwelcome distraction and blamed Ferguson for that. He considered it unprofessional, the manager putting a personal issue before the club.

‘If anyone thinks all that stuff was good for Manchester United, they are living in cuckoo land,’ he says. ‘How it can be helpful? He would go on about distractions with player contracts or whatever. I think that was a distraction. All the negative media. They were saying that when I left. A lot of negativity saying all this on MUTV. But that’s all I did. What happened with the horse was not good for the club.

‘I was like “knock it on the head”. The situation wasn’t helping anyone. I wouldn’t say it was draining us in the dressing room but it wasn’t helping us. He needed to get rid of that environment.’

Ferguson attempts to embrace Keane ahead of extra-time during the 2005 FA Cup final

Keane, Ferguson, David Beckham and Ryan Giggs at a press conference in Tokyo in November 1999

Ferguson poses at the launch of his autobiography in October of last year

The fact that he could even discuss the matter with Ferguson remains a measure of the relationship they had. But he is dismissive even when I mention that line in Ferguson’s first book about feeling privileged to work with him. ‘Never read it,’ he says. ‘The only thing I remember is the quote about how he’d enter me to win the Grand National. But that was all nonsense.

‘When I joined United I remember Robbo, Brucie and Palli [Gary Pallister] being upstairs at The Cliff [United’s former training ground] having a cup of tea with the manager. I never wanted that, even when I was captain. Don’t think I was going into the manager’s office every week saying we need to do this or that. I went into his office on four or five occasions in all the years I was there. People think we had this cosy relationship. It wasn’t the case.’

Beyond his family and closest friends, Keane does not seem to do cosy relationships with anyone. In his first book, 12 years ago, he wrote, in that collaboration with Eamon Dunphy, that a visit he received from Mick McCarthy made him more uncomfortable because he never enjoyed having visitors at his house.

He claims to have mellowed, although not much. ‘When I was a kid in Ireland we didn’t have many visitors to our house,’ he says. ‘That’s where you draw that line. This is my professional life and this is my home life. Of course people have been in my house but not every Tom, Dick and Harry.’

The book does offer a more vulnerable, human side of Keane we have not really seen and there are some wonderful lines. He reveals how he started to read The Chimp Paradox by Dr Steve Peters. ‘The chimp is running the show,’ writes Keane. ‘I tried to read it — I’m open-minded — but my chimp wouldn’t let me.’

Keane and Ferguson celebrate winning the FA Cup on May 22 in 1999 after beating Newcastle

The duo in talks in training in 2005, just before Keane left Old Trafford after a 12-year career at the club

Is he comfortable with the fact he has been so candid? ‘That was not my intention,’ he says. ‘I was not saying to Roddy I want to show another side of myself. But Roddy’s clever; he softens you up. I only got the book last week. I’d seen chapters but until you see the final draft version you don’t realise. I was thinking, “oh right, there may be too much of that”. But it’s done now. There’s no going back.’

In a discussion with the Sunday newspapers, he was asked why he had made so little mention of his relationship with alcohol.

'The beauty of the book is I don’t have to explain everything to you,’ he says. ‘People have asked me over the years. I just gave it up. I’d had enough. Particularly when I did my cruciate [knee injury]. I’m thinking I want to play a little bit longer.

Ferguson with a young Keane and former United legend Eric Cantona in 1993

‘If I have regrets, I suppose I could have been more professional when I was younger. But some of that is just being young. You’re 19 or 20. What are you going to do after a game? Go home and watch Downton Abbey? You’re going to go out.’

The book, as he said to the TV cameras, was a chance to respond to ‘the nonsense and the lies’. Not least because of the impact the stories might have on his coaching career. ‘It doesn’t help, these stories constantly coming out about me,’ he says. ‘If you were looking at it from the outside, you’re going to be thinking “I wouldn’t touch him”.’

After seeing his Sunderland side lose 7-1 to Everton in 2007, Keane admitted in his book to spending 48 hours in bed. ‘There was nothing wrong with that because people wouldn’t have wanted to see me,’ he says.