I used to do a bit of boxing as a kid. I wasn’t too good — Sugar Puff Cascarino, they called me. Roy Keane boxed, too, and I hope he wasn’t any better because he’ll probably want to chin me for saying this: Roy, you’ve bottled it. The first sign of turmoil in your management career and you’ve walked away, thrown in the towel. You may not see it that way, but what other interpretation is there?

When the going gets tough, you head for the exit. And you’ve got previous. Saipan, 2002, when you stormed out of Ireland’s pre-World Cup training camp, slagging off the players and giving Mick McCarthy, the manager, both barrels. That TV interview when you ripped into your Manchester United team-mates — inviting trouble and sealing your fate, much like last week, when you made comments about your future that undermined your position and created uncertainty. That’s three times in six years.

So as hard a man as you are, and though you were never a shirker as a player, I have to conclude that you’ve not wanted to face the challenge of digging deep and turning around Sunderland’s season. And it’s finished your managerial career. You grasped your big chance for two great years and then you threw it away.

What chairman would employ Keane now? Why would anyone want to take the risk on a man who might just walk away in a year, or 18 months, if there’s a bit of pressure on him? Clubs will look at Keane and see a man they may not be able to trust or feel confident in should the club hit rocky times, and they will wonder if he would leave them in the lurch, as he has done at Sunderland. At 37, it’s not like his personality is going to change.

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Of course, not many would have employed Keane in the first place. He owes his opportunity to Niall Quinn, the Sunderland chairman and his former Ireland team-mate. Niall said all the right things, praising his departing manager yesterday and doing everything to avoid undermining him, but it’s ridiculous that it has come to this so quickly when only two wins on the bounce would lift the team back into mid-table in the Premier League and the side were performing well only a few weeks back.

But look who Sunderland face tomorrow: they are away to Manchester United. I can’t help wondering if wanting to escape a humiliating beating at Old Trafford and avoiding the glint of triumph in Sir Alex Ferguson’s eyes was a factor in the timing of his decision.

We can question some signings — several players were definitely overpriced and the squad was too large. But it’s not footballing decisions, not tactics or transfers, that have ultimately caused his downfall. It’s his lack of personal skills, that’s where it has fallen apart. His inability to deal with human beings. You can’t treat people with contempt and disrespect and expect to get away with it in the long term, especially when you’re no longer as successful as you were. It is a lesson Keane should have learnt from the way he was bundled out of Old Trafford, when his performances were in decline and Ferguson decided he had become a liability.

As a manager, you have to be diplomatic, take an interest in your squad, show you care on a personal level, know when to keep your distance from players and when to get close.

But Keane only does distance, he doesn’t do warmth. Bonding? No chance. It doesn’t matter how powerful or influential you are, whether board member or kit-man, he won’t want to be your friend or develop any relationship with you beyond the bare minimum. Keane said last week that he didn’t think the players cared about him, and no doubt the feeling was mutual.

What now? He’ll just shrug his shoulders, get back to family life, no regrets. There might even be something inside him that gets a kick out of the chaos he creates — a certain pride in being so different from everyone else. The dog will get a few extra walks. But it’s a shame the owner didn’t stay put.

Red cards, rows, Rolexes...and prawn sandwiches

April 1995: Sent off for stamping on Gareth Southgate during FA Cup semi-final replay against Crystal Palace. Fined £5,000.