At the renowned Peacock Gym in Canning Town, east London, the banter is flying faster than the fists. "Hey, it's the Welsh Don King," someone cries as Colin Charvis, one-time Wales captain and possessor of a proud Afro, tapes his fists for some tentative sparring.
Charvis is one of eight former rugby union and league players training here for a night of white-collar boxing in support of charities and the testimonials of Mark Cueto and Tom Shanklin. There are nerves and there is excitement. The PR blurb for "Rugger in the Ring" unashamedly links the event to the fight against depression among retired sportspeople; a once-taboo subject no longer swept under the canvas.
From Marcus Trescothick and Andrew Flintoff in cricket to boxers Ricky Hatton and Frank Bruno and rugby's John Kirwan, Duncan Bell and Jonny Wilkinson, the dangers to mental health posed by the unique challenges of professional sport – the weekly battle to get selected and succeed; the abrupt loss of the glory and adrenaline when a ludicrously short career is over – are increasingly acknowledged and understood.
Bill Bradley, an NBA basketball player turned US senator, wrote this searing summary in Life on the Run: "There is a terror behind the dream of being a professional ball player. It comes as a slow realisation of finality and of the frightening unknowns which the end brings."
Martin Offiah, Matt Perry, Lee Radford, Sean Long, Alan Quinlan and Brian McDermott are on the bill, and Charvis's opponent will be Fereti Tuilagi, the former St Helens and Leicester Tigers player who will have his brother Manu, the current England centre, as his cornerman.
Each of the novice boxers has been allocated a paid trainer for two months to get them fit and pick up the basics. "Freddie" Tuilagi has slimmed from 118kg to 110. "I feel rejuvenated and I feel better about myself," he said. No one would associate Tuilagi, the eldest of seven brothers, a crushing tackler and now a players' agent and coach, with self-doubt. Yet after he finished playing in 2006 he let himself go.
"I wouldn't say I was depressed, I just lost my way," Tuilagi recalls. "I was drinking a lot and putting on weight. You look in the mirror and see it but you can't help yourself.
"When you have played full-time for 20 years it's all you have known. You no longer have that chance to run over someone, to entertain and perform in front of big crowds. It's hard to explain."
Offiah, a 46-year-old legend of the wing, though not yet the ring, says: "When you retire from playing sport you say goodbye to something you love. We are all of us looking for that rush again."
Rugby players have many fears, almost always unspoken, and mostly to do with loss – of the mapped-out daily routine, the camaraderie and the sustaining vigour of a prolonged youth. Few are likely to earn enough to be set up for life.
There is the uncertainty over what to do next, often without qualifications for a second career. A study by the New Zealand Rugby Players' Association found one in three players will experience depression, anxiety or stress after retirement. Shockingly, the press coverage of the post-career suicides of NFL players Junior Seau, Dave Duerson, Andre Waters and Ray Easterling speculated that repetitive brain trauma was a factor. Rugby has yet to come to terms with those implications.
Fears over injury and non-selection and doubts over self-worth can also afflict the apparently successful while they are playing. Kirwan, the former All Black, and Bell, the Bath and England prop, described living with the "hidden illness" for years. Yet when Mind, the mental health charity, polled 2,000 British adults this year only 52 per cent responded that if sporting figures had a mental health problem their family should be told; just 48 per cent said their manager should be informed.
Mind say one in four adults experience a mental-health problem; they describe depression as: "in its mildest form… just being in low spirits. It doesn't stop you leading your normal life, but makes everything harder and seem less worthwhile. At its most severe, major depression can be life-threatening, because it can make people suicidal or simply give up the will to live."
Quinlan, the former Ireland flanker, has spoken at seminars about the need to support the depressed. After an unaccountable loss of form early in his career he dissolved into tears, crying, "Help me" to the then Munster coach Declan Kidney. To the spectator, "Quinny" was ebullient: part joker, part great defender. But he needed a psychotherapist after blowing his chance of a Lions tour in 2009 with a ban for eye-gouging, and he had to cope with separating from his wife the following year.
"Professional sport is getting more and more about performance, about winning, and it doesn't always work out well for people," says Quinlan. "I can look back now and reflect that I had a fulfilling career. But that whole thought of it coming to an end is tough to deal with."
So "Rugger in the Ring" is both a welcome source of income – from £20,000 to £35,000 if they win through to, and do well in, a box-off in Dublin next March – and inspiration. David Barnes of the Rugby Players' Association says: "There is an argument over whether a rugby player would be naturally more resilient or more vulnerable due to the pressures of the job. John Kirwan says depression is something you can treat. Educating the players on the signs and symptoms is important. So is coaching the coaches. A coach with an open mind will find he has a better player."
Suitable cases for treatment
Depression struck the former wing at the height of his career of 63 Tests for New Zealand. From believing a poor performance to be "an absolute disaster" he reached the stage where he "didn't care about football, it was just about survival". Kirwan later wrote a book, All Blacks Don't Cry.
England's most famous fly-half revealed in his autobiography last year how an obsession with practice combined with multiple injury lay-offs drove him to depression in 2006. Through sessions with a therapist, and with the help of Buddhist teachings, he came through bouts of self-harming.
The former Munster and Ireland flanker endured serious doubts over his self-worth towards the end of a successful playing career, but was helped by sessions with a psychotherapist. He now speaks for the Lean on Me campaign to support people with depression.
"Rugger in the Ring" is at the Grange City Hotel, London, on 6 November. For tickets, call 07812 800 125 or email firstname.lastname@example.org. IoS readers can obtain a 20 per cent discount by quoting ref IND10