The late nights were half supervision, half self-medication. When Don Bradman was Australian cricket captain, he detailed the assistant manager, Arthur James, to stand guard at the hotel lobby and note the times of the cricketers' return. And what thanks did these backstage heroes get? Constant razzing from the players or, in James' case, the daytime duty of giving massages to the same felons who had tried to sneak past him at dawn.

The New South Wales State of Origin assistant team manager is also a short-statured Celt with a receding hairline, but you won't see any of the players patting him condescendingly on the head or pulling pranks at his expense. Mark Donaldson might be the smallest man on the team, but he is there because the footballers, hearing his stories, look up to him as to a giant.

Donaldson would hate this attention. He'd rather disappear behind a pot plant - something he could convincingly do - than speak about himself. When the then chief of army, Ken Gillespie, told Donaldson in early 2009 that he was to be the first Australian to receive a Victoria Cross since the Vietnam War, Donaldson's first impulse was to refuse the award. He didn't like being singled out, and, as a Lance Corporal in the Australian SAS, he did not want to be put in cotton wool.

He wanted to go back to the frontline in Afghanistan, where his actions on September 2, 2008 had earned him the VC. Donaldson felt he owed his mates, his regiment and himself more frontline service, and did not want to be a protected VC winner. Only when the army agreed to let him go back did he accept the award. He undertook three further tours to Afghanistan, in the last of which he received a bullet in his thigh which he still carries. He wrote a best-selling book, The Crossroad, on which - declaration of bias - I worked with him, and I consider him a friend.

Last year, Laurie Daley had Donaldson come into the NSW squad in a mentoring role for the second and third Origin matches. You could see him in dressing room shots, off to the side, observing and, in the end, commiserating. He left such a powerful impact on players and staff that he was invited to come back in 2017 with the formal title of assistant manager. He can be seen in the background again this week, yes, carrying bags and making sure the details were taken care of, but his real work would be carried out in quiet conversations behind closed doors.

It's not for his logistical prowess that Donaldson is with this group; but it's not about telling war stories either, or drawing false comparisons between the frontline in Afghanistan and the advantage line at Lang Park. His presence and influence with the group say much about Daley's leadership ideas, because Donaldson is not there as a war hero but as a regular bloke, not much older than the players, who has survived extreme setbacks and emerged intact. He won the VC for conspicuous bravery, but he is also a model of inconspicuous resilience.

The trauma in Donaldson's upbringing draws as much respect as his military achievements. He was a typical teenaged scallywag in Dorrigo on the NSW north coast when his father, a Vietnam veteran who refused to talk about his war, died from a catastrophic heart attack while in his dentist's chair. A little more than a year later, Donaldson's mother disappeared and was presumed murdered by a man who was seeking her attention. That man committed suicide the day of her disappearance, and her body has never been found.

Donaldson and his brother were cared for by Legacy. At the time of his mother's death, Mark was a dreadlocked, body-pierced graphic arts student running wild in Newtown and gathering interesting experiences. The double impact of his parents' deaths sent him into an odyssey of sometimes reckless adventure in Australia and North America. He worked on the roads and as a snowmaking machine operator before setting his sights on the ultimate personal challenge. He joined the Australian Army at a relatively advanced age and progressed to SAS selection at unprecedented speed.

On September 2, 2008, Donaldson's convoy in Afghanistan was ambushed by an overwhelming Taliban force, leading to the biggest enemy contact Australian soldiers had been involved in since Vietnam. Donaldson survived the four-hour running battle, but at the end he looked back into the danger zone and saw a comrade lying in the dirt. Against his superior's wishes, he ran back into the field of fire, picked up his mate and carried him to safety, the bullets kicking up the dirt around him like raindrops in a thunderstorm. The comrade, a wounded Afghan interpreter, survived and Donaldson won the VC. He saw many others achieving what he felt was more than he had done, and considered his work unfinished. Indeed, he proved his bravery again and again on his subsequent tours.

The best thing about Donaldson being in the NSW Origin set-up? He is no rugby league groupie. He's not starry-eyed over Jarryd Hayne.

Growing up, he preferred karate, hooning around on bikes, messing around with fireworks, and later surfing and snowboarding. He played soccer instead of rugby league to get out of the shadow of his brother Brent, who was the family sporting talent.

He is not among the Origin stars to admire or suck up to them or tell them that he might have fought in a war but they are living his dream. They are not. He is one person brought among these athletes who does not hold them in childlike awe. The flow runs the other way: footballers who meet him relearn the ability to respect someone who never aspired to be one of them.

Should NSW beat Queensland, Donaldson's role will be acknowledged. But winning is not the point - and this is why there is so much to like in Daley's embrace of this man. Donaldson is not there to give Daley's players a winning edge, but to widen the scope of their experience, so that they may come out of the next six weeks with larger minds and fresher outlooks.

They might win or lose the series, but either way they will be richer for crossing paths with this humble, likeable, extraordinary ordinary Australian, and whatever happens, they will leave the camp better off for his friendship. And if the Queenslanders are smart, at some point they will seek him out too.