Such is his success and longevity in the competition – the formidable forward made his debut with Bradford Bulls as long ago as 1999 – he has become a part of its very fabric.
But he maintains that, as he enters his 38th year, this will be his final season even though the tireless prop is playing some of his finest football yet.
He has shelved his initial plans for retirement once before but it seems there will be no repeat.
In March, 2012, after signing a new two-year deal at Leeds Rhinos and shortly before stepping down as England captain, Peacock suggested that contract would take him to the end of what has been an illustrious, remarkable career.
But he realised there was still more to come when so imperious for the club in 2013, almost winning Man of Steel as Super League’s most dominant player, and, so, he signed another two-year deal 12 months ago.
Many observers felt he was Super League’s best player last year, too, and should have added to the accolade he last won in 2003. This Indian summer is not fleeting.
That contract expires at the end of the forthcoming season but first Peacock will celebrate a long overdue testimonial at Headingley tomorrow when his home-town club take on Bradford, with whom he won Grand Finals, Challenge Cups and World Club Challenge titles aplenty.
This week, therefore, as well as reminiscing on a career which has seen him lauded as one of the modern era’s greats, there have been inevitable questions about whether 2015 really is the end.
Asked if anything could change his mind on retirement, Peacock said: “It’s a difficult question but, at this moment, no.
“I’m looking for this to be my last season at Leeds. It will be the right time to bow out. It feels like that, especially after this pre-season! There are only so many times you can push yourself and have a desire to do things so, at this moment, no.
“I don’t think they (Leeds) will come to me again. I think they are trying to lower the age here.
“In the middle of the season I might struggle with how hard the games are. If they were going to ask me to play on it would be now before we had played a game.”
Leeds coach Brian McDermott, who played alongside a tyro Peacock in a Bradford pack that annihilated so many sides early in Super League’s evolution, believes he is the best prop the competition has ever seen and it is hard to argue with that.
Yet people often forget much of Peacock’s early success came at second-row and it is largely since his switch to Leeds in 2006, that he has developed into a front-row of such distinction.
That also serves as a reminder of just how much glory ‘JP’ has achieved. The seven trophies with Bradford (Super League 2001, ’03, ’05, Challenge Cup 2000, ’03 and World Club Challenge 2002, ’04) would ordinarily be a terrific bounty for any player yet, despite not moving until the age of 28, he has actually bettered that total since.
Finally lifting the Challenge Cup with Leeds last August, at the third attempt, signalled his eighth trophy success for them after five Grand Final triumphs (2007, ’08, ’09, ’11 and ’12) plus World Club Challenges in 2008 and, again, three years ago.
“I have been in the right place at the right time with two great teams,” is Peacock’s modest reasoning.
“You can be a good individual but you need to play alongside good individuals and have great coaches. I was fortunate to be at Bulls when we had that and a sustained period at Leeds where we’ve had all that, too.”
Of course, Bradford’s trajectory since Peacock’s departure has been shockingly downhill to the extent they have never reached Old Trafford or a Challenge Cup final again, have been blighted by financial problems and, after suffering an unthinkable relegation last term, will now use tomorrow’s game as preparation for next month’s Championship opener at Leigh.
The decline can be traced back to 2005 when Brian Noble’s Bulls side reached their fifth successive Grand Final, defeating Leeds in Peacock’s last game, but then saw its main body break up.
Of that vintage, captain Peacock headed to Leeds, Robbie Paul joined Huddersfield Giants, Great Britain utility Leon Pryce ventured to St Helens, hard-working Lee Radford went back to Hull FC and, not long after, Great Britain prop Stuart Fielden was sold for a world record £440,000 to Wigan, who had earlier tempted Noble over, too.
But, from it all, Pryce said this week the worst thing Bulls ever did was let Peacock go.
“It’s kind of Leon to say that,” he said. “I think it was probably because I was the first to make my mind up to leave Bradford.
“After that, a lot of people decided they were also ready to move on because of a bit of mis-management from the club.
“We had a great team and there were a lot of good guys. Leon was one of those.
“It is disappointing how it has gone for Bradford from then. That period of success was an amazing time to be at the club.”
Peacock, who amassed 47 Tests with England and Great Britain, was due a testimonial at Odsal in 2006 but forego that to switch to Leeds, the side he supported as a boy.
As career moves go, it was a brilliant decision.
“It’s been a huge part of my life for the last 10 years,” added Peacock, who, alongside the likes of Kevin Sinfield, Rob Burrow and Danny McGuire, has helped form one of the sport’s most dominant sides.
“It has been more than a job, more than a sporting career. It’s about the people you meet along the way; players, coaches, the people that work at the club.
“There have been some fantastic people here and they are as much part of my good times over the last 10 years has have been the successes.”
Leeds have failed to reach Old Trafford in the last two seasons, however, something Peacock hopes to remedy in 2015.
No-one has more Grand Final wins than his eight but a ninth would be a perfect denouement.
“That’s the fairytale finish,” admitted the Yorkshireman, awarded an MBE in 2012. “That’s the one all players want – their last game to be at Old Trafford and winning there. But there are a lot of other clubs wanting to win it and not just because they are ending their careers; because they are good enough.”
But what if Bradford offered him a swansong in 2016? “I couldn’t answer that question until it came along,” he said. “I am a Leeds player. I had great times at Bradford and hope they do get back in Super League for 2016.”
First, for once, he will “make the most” of being the centre of attention tomorrow and enjoy the occasion, at least before the action gets underway. And then that famous steely determination will instantly be flicked on again.
The Jamie Peacock story...
1977: Born December 14 in Leeds
1999: Makes Bradford Bulls debut
2000: Wins Challenge Cup against Leeds Rhinos and makes England debut v Russia in World Cup
2001: Lifts Super League title and scores try in just 86 seconds of his Great Britain bow as they beat Australia
2002: Features as Bulls defeat NRL champions Newcastle Knights to lift their first World Club Challenge
2003: Part of Bulls side that wins Grand Final, Challenge Cup and League Leaders’ treble. Named Man of Steel.
2004: Captains Bulls to World Club Challenge success over Penrith Panthers
2005: Leads Bradford to Grand Final glory against Leeds in last game before leaving. First to prosper from third. Named Great Britain captain.
2006: Leads Great Britain and scores as they beat Australia in Sydney, his “greatest” RL achievement.
2007: Wins Grand Final with Leeds against St Helens
2008: Leeds champion Melbourne Storm in WCC and repeat Old Trafford success
2009: Leeds secure third successive Grand Final win
2011: Another Grand Final triumph against Saints
2012: Challenge Cup final loss v Warrington and retires from internationals but wins eighth Grand Final. Earns MBE
2014: Wins Challenge Cup against Castleford Tigers