David Warner and Steve Smith. AAP

The Australian cricket captain Steve Smith and vice-captain David Warner, along with Cameron Bancroft, made a scarcely believable, terrible decision to tamper with the ball during the third Test against South Africa in Cape Town last week. They have rightly been stripped of their leadership roles and will serve lengthy bans from the game. They no doubt reflect on that appalling decision and wonder how on earth they could have made it.

I had the privilege of working with the Australian cricket team for five years up until July last year as their doctor. For nine to 10 months of each year I lived, ate, worked, and laughed with a great bunch of young men who were committed to ''being number one in the word in all three formats'' – Cricket Australia’s mantra.

I first met Smith in England in 2012 when he was part-time spin-bowler and tail-end batsman on the fringes of both the one-day and Test teams. I watched him develop over the ensuing five years into the best batsman in the world – a remarkable transformation.

In 2015, I had my doubts whether he was ready for the demands of captaincy, but I watched on as he impressively rose to the challenge of leadership, and became an even better batsman.

It was with some trepidation that I first met David Warner in India in 2013. His reputation as ''The Bull'' (an aggressive big hitter who was difficult to deal with) preceded him. And that was (and still is) an image he portrays. The reality was very different. Warner was always interested in other people, and keen to learn about life. Far from being difficult to deal with, he totally reformed his diet and fitness (I suspect it was partly to improve his cricket, mostly to impress Candice!), and set about proving himself as a Test batsman with the technique and concentration to complement the power and skill he’d shown in the Twenty20 format. And as always, he provided the sharp-edge thought necessary to succeed in the harsh and competitive environment of Test cricket.

So if, as I suggest, Smith and Warner are basically good people, how did they come to make what is arguably the worst decision in the history of Australian sport? We need to understand those reasons in order to prevent a similar occurrence in the future.

After 30 years of being around elite sportspeople and teams both here and overseas, I have had first-hand experience of the sort of pressure that teams and individuals operate under. I have observed at close quarters the likes of Cathy Freeman and our athletic team at Olympics, Commonwealth Games and World Championships, I have watched AFL players prepare themselves for grand finals and other big games, I have been with the Socceroos at the World Cup and Liverpool at English Premier League games in the spine-tingling atmosphere at Anfield – all under immense scrutiny and pressure to win. Some coped better with that pressure than others.

Until working with the cricket team I did not appreciate the physical and mental brutality of a five-day Test match. The pressure to perform and to win is immense. The Australian public believes that the Test cricket team is “our team”. We all have an opinion on who should be in the team, and have a lot of passion invested in their fortunes. We’re accustomed to winning and are very intolerant of losses such as those in the home series against South Africa at the end of 2016, which was accompanied by front-page newspaper headlines demanding change. As a result, half the team was sacked.

The players and staff feel that pressure. They are on tour for most of the year while at the same time trying to have some sort of normal existence with partners and family. If you play all three forms of the game – interestingly Smith and Warner are two of the few who do – you rarely get to sleep in your own bed at home.

As well as lacking a regular home life, modern Test players inhabit an unusual social environment. Often unable to leave hotels when on tour for security reasons, teams and players can become highly introspective. The rapid development from junior cricketer to professional can mean that players miss life experiences most of us take for granted. And with little preparation, they are thrust into an environment where every on and off-field move is recorded, and all of their professional and personal failures are magnified in front of the world.

Sport is littered with stories of otherwise sensible people losing their perspective and becoming obsessed with winning. Essendon and Melbourne Storm are two Australian examples that spring to mind, but the trend exists across all sports and around the world.

This Australian tour of South Africa has been extremely stressful with both sides behaving poorly and a generally unpleasant atmosphere. Warner has had to deal with verbal attacks on his family, while Smith has ultimate carried responsibility for the team performance. Both would have been dealing with the additional burden of poor form.

It is worth careful examination of the role that fatigue, pressure, and stress played in Smith and Warner’s decision-making. Greg Chappell has stated that he was in no fit state to be captain when he made the ill-fated decision to ask his younger brother Trevor to bowl the infamous underarm delivery against New Zealand in 1981. Every Australian captain since then has had moments where the demands of their role reduced the quality of their judgment. Given their actions, one has to conclude that Smith was in a similar position during this last Test match.

We always joke that the captaincy of the Australian cricket team is at least the second-most important job in the country, but for many it’s number one. The captains have little formal leadership training, and are just expected to do the job. Easier said than done. At the same time they have to maintain their own high levels of performance, which demands a huge commitment of physical and mental energy.

Yes I know what you are all saying. These guys get paid millions of dollars to shoulder the responsibility. But no amount of payment or sponsorship will endow players with superhuman physical and mental powers. They remain as human as the rest of us.

Smith, in particular, has gone from being probably the most popular sportsperson in the country (Australian of the Year, according to one newspaper), to being a figure of ridicule and contempt. I would argue that neither extreme is appropriate. Smith is a decent man putting his all into a difficult job. In a desperate attempt to turn around a Test match that was slipping away, he suffered a serious lapse in judgment with disastrous consequences for himself and the game of cricket in this country.

We must try to learn from this, and ensure that future captains are given more support and not put in situations where their judgment can be so clouded. The players should be playing less cricket, and breaks away from the game need to be included in the schedules of all senior players. Perhaps it is time to consider complete separation of the Test and ODI/T20 teams.

The culture of win-at-all costs needs to change. As part of that, the Australian public need to accept that defeat does not mean the players are not giving it their all. The public and media are all too happy to pile on the pressure and expectation, and then call for heads to roll when its effects take their toll.

I worry about these young men and how they will handle the enforced break. Hopefully they will take the opportunity to broaden their life experiences and equip themselves for the pressures they will be under if they return to the Australian Test team. And I hope they do return. They are not bad people. They just made a very bad decision in a very stressful situation.

For now, they are having the book thrown at them, and rightly so. But when the catharsis is done, it’s time to take a look at the pressure we put these people under and understand how to create a better environment in the future.

Peter Brukner was Team Doctor of the Australian cricket team from 2012-17.