A solid professional working his way around English football in a career spanning 16 years to the point where he was named as the head of the players' union in England in 2010.
The 33-year-old is a well-spoken and educated man, and was once even present on the BBC's political question-and-answer programme, Question Time, in January 2011 where his appearance was warmly applauded by The Guardian television reviewer Rob Bagchi.
He was once a contestant on Channel 4's words and numbers quiz Countdown, and is an ambassador for football's Kick It Out campaign, which supports inclusion and equality in the game.
Carlisle, who retired from the game after playing for Northampton Town in the League Two playoff final defeat to Bradford City, is married and has two young children, as well as a daughter from a previous relationship. He appears to possess an idyllic life.
However, in his BBC Three documentary Football's Suicide Secret, Carlisle admits he was on the verge of taking his own life at the age of 21.
After picking up a serious injury during a match against Queens Park Rangers, the Preston-born defender believed his career and his life were over, as he told BBC Three.
I was a 21-year-old professional footballer for QPR and the England Under-21s. I had a nice flat, a nice car and a loving family.
My irrational mind had made me think suicide was a rational action though. So I went to a park near my home in Acton armed with lots of painkillers and thought: "I'm going to take all these pills and kill myself, because I'm no use to anyone".
I sat on a bench in that park, washed the pills down with a can of beer, and waited for it to happen. In the end I was incredibly lucky, because my girlfriend found me and I was rushed to hospital in time to have my stomach pumped.
It was a stunning admission for anyone familiar with Carlisle, who has become a more prominent media figure through his role with the PFA.
Consider his words carefully and match them to the man you know from his media appearances. This isn't a man found hidden away from the world in a bedsit with the walls and windows painted black.
Such are the highs and lows of football that, for every Wembley winning goal, there are many more careers on the scrapheap through injury, loss of form and managerial selections.
But suicide and mental health remain almost taboo in the game, despite the tragic death of Wales manager Gary Speed in November 2011 and the current issues surrounding former England international Paul Gascoigne, as reported by Jeremy Armstrong of the Daily Mirror.
Speed was enjoying a successful period as Wales boss, but was found hanged in his garage just hours after appearing as a guest on the BBC's Football Focus programme, as Chris Bascombe of the Daily Telegraph reported.
Gascoigne was detained under the Mental Health Act in 2008, as Nick Allen of the Daily Telegraph reported, and underwent rehab at a clinic in Phoenix, Arizona, earlier this year, as BBC News reported.
Another player featured in Carlisle's documentary was Germany goalkeeper Robert Enke, who killed himself in November 2009 after battling depression since 2003, as BBC News reported.
But Speed, Gascoigne and Enke are merely the peaks of a major iceberg, the high-profile names in the ongoing battle against depression in football.
Former Aston Villa midfielder Lee Hendrie and ex-Norwich City striker Leon McKenzie both spoke eloquently about their own suicide attempts during the BBC Three documentary, as BBC Sport reported.
Hendrie and McKenzie both survived but neither was able to talk to someone about how they were feeling, and that is where Carlisle is determined to ensure help is available within the game.
As chairman of the Professional Footballers' Association, I was shocked to hear that Leon had phoned my organisation to talk about his depression yet had not been given an understanding response.
It was very telling that neither Lee nor Leon felt they could talk to anyone about their problems.
We need forensic research about the potential triggers for depression. For example when a player retires, his chances of getting clinical depression go up 40 percent.
Other common triggers are injury, being transferred, the inability to separate home and work life. Yet I must also point out that there is often no logical trigger because depression is an indiscriminate illness.
For anyone affected by the loss of someone to suicide and depression, the documentary carried additional poignancy at the ripple effect of death in such a way.
The questioning of why and could we have done more loom large for friends and family, as Carlisle discovered when he spoke to Lesley Speed, the sister of Gary, as Laura Caroe of The Sun reported.
To the outsider, the world of the footballer is one of adoration and vast riches, but for every leading star there are several more journeymen being barracked from the terraces.
Every club has its scapegoat in the stands, the name greeted with relative silence, muted applause or even outright abuse as it is read from the tannoy.
Imagine going to your job and being berated by several hundred others watching when you do something wrong.
Carlisle has exposed the underside of the Beautiful Game and is determined to change things for the better for sufferers. We should all be grateful that he is still with us to do so.
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