He's fit, he's ripped and he's glowing with good health. He's also about five stone lighter than the washed-up, pizza-chomping, bloated has-been he was just over three years ago. In other words, he is the kind of inspirational figure Edinburgh need right now.
For just as Atiga brought himself back from the brink when he decided to get his act together and return to rugby in 2010, Edinburgh must consign last week's calamitous 45-0 loss to Saracens to history's dustbin when they line up against Munster at Thomond Park today. After the giddy heights of their run to the semi-finals of last season's Heineken Cup, a second successive defeat would almost certainly bring their interest in this season's competition to a close. The Limerick ground is not the sort of place you would choose for a resurrection, but Edinburgh need one today.
Atiga has been brought into the capital side's midfield at the expense of Matt Scott, the Scotland international centre. Even Michael Bradley, the Edinburgh coach, has admitted that today's selection is something of a gamble, but it is not as if he has many chips to play. And if Atiga can find just a fraction of the form that once saw him billed as rugby's next global superstar, then the gamble might just pay off.
Atiga was just 20 when he was drafted into the New Zealand squad at the 2003 World Cup in Australia. The young Aucklander's rise though the age-grades had been stratospheric up to that point, and he would end the tournament as a fully-fledged All Black, by virtue of a six-minute appearance as a substitute against Tonga. A few weeks later he was crowned World Under-21 Player of the Year. Unquestionably, he was the sport's golden child.
But it was a case of too much too young for Atiga. Having been hot-housed and cossetted through the New Zealand development programme, he hit the buffers in the far crueller world of adult rugby. He struggled to make an impact in the star-studded surroundings of the Blues' Super Rugby side, failed to get back into the All Blacks squad, and by the end of 2008 was drifting badly.
"I think I had a stale period, a plateau," Atiga explains. "It was just because I was getting bored of doing the same thing each year, playing in the same competitions with the same players, the same teams and in the same role. I just got bored and wasn't as interested as I was when I was younger.
"My head was not in the right place. My attitude wasn't there and I knew that myself. At the end of October 2008 I decided I had to take a couple of months out. I made myself unavailable for Super Rugby. But then it kept going because I enjoyed it [his time out] too much. I stayed right away from rugby and everything involved with rugby."
Atiga threw himself into a marketing concern he had launched with some former school friends. Power lunches were obviously part of the package as well. The lithe rugby player became the lardy businessman as he ballooned to a size that would have prop forwards reaching for the Weightwatchers brochure. Having topped out at 120kg, or around 19st, it was only when he was invited to take part in a charity match that he began to get his head and his body back in shape. And, yet, he has no regrets. "It was a good experience, an eye-opener," he says. "It put me in an honest position where I knew exactly where I was, and where my place was outside of rugby. It was one of the best decisions I made. I think I wouldn't be playing rugby today if I hadn't done that. It made me realise how lucky we are as rugby players to be doing what we love. It's something we shouldn't take for granted.
"You can tell players things, but you don't really know it until you're on the factory floor. It's hard to get it across to them. When your contract ends, and the money stops coming in, and you have to find a new way to pay the bills, that's when you start to realise what kind of lifestyle you are living and you appreciate how fortunate you are. It's hard to get that across to people who haven't actually experienced it."
One or two Edinburgh players may have caught a glimpse of that abyss as the side caved in against Saracens just over a week ago. Atiga, still recovering from a hip injury, sat that game out, and he may never have been happier to dodge the bullet. He admits that the past few days have been tough going for the squad, hoping that a clear-the-air meeting will have helped.
The Edinburgh coaches were not invited to take part. "It was just the players," Atiga says. "We wanted to get things out, get things off our chests. It was led by Greig [Laidlaw, the captain] and it was just about how the team were feeling. We had to ask honest questions of ourselves, the things we are doing on and off the field. We had to put that on the table. Greig laid down the law about what he expected of us and how much we had to repay the management and the coaches and the fans.
"It's a hard place to be, but I had been there before. But you can stay down too long. You have to do something different and that's what we have done. Guys are stepping up to the plate now and taking responsibility."
Weighed against expectations, it was comfortably the worst Edinburgh performance of head coach Michael Bradley's time in charge. Badly timed, too, as Bradley, a son of Cork, will not savour the prospect of a repeat in Limerick today.
So did Bradley read the riot act? "I'm not going to go into detail about how I handled it," the coach says. "The message to get over was that it was unacceptable – for Edinburgh rugby, the media who write us up, the supporters, the city as a whole. You just can't do what we did last Saturday. Now we want a reaction, and a positive one. If you're asking me if they have got the clear message that last week was not acceptable then, yes, I think they did.
"We didn't have to bang their heads to get them to admit to it. They put their hands up themselves. It's a tiny consolation, I suppose, that the squad is maturing that way in terms of responsibility. Their attitude was 'we are good enough and we should have done so much better'."
Munster, having lost their own opening match against Racing Metro are equally aware what another defeat could mean. European giants a few seasons ago, they are now in a rebuilding phase, and today's game will be a measure of how that process is going. There will be an unmistakeable whiff of desperation around events at Thomond Park today.