The last time Glen Jackson set foot on the holy acres of Twickenham, he did everything in his power to guide his friends and colleagues from Saracens - fullback Alex Goode and lock Mouritz Botha among them - to a first Premiership title and damn nearly succeeded.
A few days from now on the same rectangle of grass, he could easily be the man who prevents those self-same players from helping England to victory over Fiji.
"It's going to be a slightly odd experience," admits the former first-five looking ahead to his first test as a referee.
"There will be lots of nerves. Basically, you don't want to make a big cock-up. As a player, you're excited at the prospect of making the big play; as a ref, the excitement comes from the challenge of not mucking up the big play. I'm not thinking about the pressure, though. I'm thinking that this is a dream come true. To be awarded my first international at a place like Twickenham, where I played my last game - I'd be pretty greedy if I asked for anything more."
Jackson the first five-eighth called it a day after that compelling final against Leicester 2 years ago, having decided it was time for a new dawn in his career.
Even before he joined Saracens from Bay of Plenty in 2004, the idea of taking up refereeing had started to germinate. There were only two questions: when to make the leap, and how quickly it would take him to reach the top rank.
"My last season at Saracens was so enjoyable, especially the final four or five months when we played some wonderful rugby, that I was half-tempted to keep going for another year," he says, modestly declining to speak directly of his own glorious run of Indian summer form at the heart of midfield. "Also, there was the coaching option. But I'd had things mapped out in my mind for quite a while and decided to stick with the plan, which turns out to have been a good call."
By opting for the road less travelled - very few professional-standard players consider the whistling trade as a retirement option - the 37-year-old from Feilding has set a new template for refereeing at international level.
Mentored by experienced official Lyndon Bray, he found himself controlling deadly serious ITM Cup games within a year of returning home. By the end of the 2011 season, he was on the Super 15 roster. This was not mere fast-tracking. This was tracking at the speed of sound.
"There has been a lot of quick learning along the way and to a degree it was an experiment, both for myself and for the New Zealand union," he says. "There weren't many fulltime refs in the country when I took it on - only five, I think - so there was obvious potential for progress if I could get things right. That wasn't a given and it was understood by both sides that if it wasn't working after a year, that would be the end of it. It just so happens that each time they pushed me up a level and said, 'Let's see how you go,' I went well enough to justify it."
Jackson ran into a short, sharp fusillade of controversy last weekend after refereeing the ITM Cup final between Auckland and Canterbury. Wayne Pivac, the defeated Auckland coach, highlighted a couple of contentious decisions that in his view changed the match, and the comments were given plenty of airtime. But Jackson has yet to experience the kind of firestorm that drove his countryman Bryce Lawrence into premature retirement after the World Cup quarter-final between Australia and South Africa last year (Springbok supporters donned T-shirts with the legend "Bryce Lawrence Hunting Party"), or been made to suffer as English official Wayne Barnes did in the 2007 tournament.
Interestingly, Jackson identifies Barnes as one of his closest friends in the refereeing fraternity. "We get on particularly well," he says of the man castigated from Whangarei to Invercargill for his performance in the quarter-final between France and the All Blacks. It is not stretching the point to suggest that this makes Jackson as unique a New Zealander as he is a referee.
"I've been on both sides of the fence and I understand the difference. Make a mistake as a player and it's accepted. Make one as a referee and it's another story. I said to my family right at the start that this would be a tough path to follow."
And how has his family taken to it? "Pretty well," he says. "I have a son of 5 and he loves it. While all the other kids in the playground want to be Richie McCaw, he walks around pretending he has a yellow card in his hand."