The Queenslander has become one of Canberra's favourite adopted sons in his 13 years with the club and will be the first player without the last name Croker to bring up the triple century in the famous green strip when he runs out at Belmore Stadium on Sunday.
A consummate team player, the man affectionately known as Papa just wants to focus on the task at hand, with a red hot Canterbury side standing in the way of the Raiders and a top eight spot.
But no-one at the club was going to let the milestone pass without making a monumental fuss for the larger-than-life prop forward.
Front row partner Joe Tapine joked his teammates would be sporting the limited-edition swimwear commemorating Papalii's legendary 2020 ankle tap on teammate Jamal Fogarty during his erstwhile stint at Gold Coast.
"Personally, it's more than football what he means to me," said Tapine.
"He's part of my family. Me and his family are so close and our kids have grown up together. It means a lot to me to be there standing next to him."
Cherishing the loyalty the Raiders have shown in him, Papalii has long been set on being a one-club man.
But it very nearly didn't pan out that way.
A fresh-faced Papalii signed with Parramatta in 2013 to play under then-Eels coach Ricky Stuart but back-flipped to stay at the Raiders.
So instead, Stuart came to Canberra to work with him.
"It's probably the best knock-back by a player that I was recruiting that I've had," Stuart joked.
The Raiders great placed Papalii alongside Glenn Lazarus as one of the leading props to ever play the game.
But his biggest praise was reserved for his qualities as a human being.
"Papa is such a genuine human and the respect he has in the game ... is probably as high as I've seen in an individual player," Stuart said.
"I don't know anyone who doesn't like Josh Papalii."
His feelings for Stuart are mutual.
"He's a better man than he is a coach," Papalii told AAP.
"We're very close off-field. He'll call me on my days off and check in with me and my family. That's why I love playing for Stick, I didn't want to play for any other coach."
As tough as he is on the field, Josh Papalii has also been feted for his character off the field. (Mark Evans/AAP PHOTOS)
Of the 51 players to reach 300 first grade games before Papalii, only eight played the majority of their footy in the front row.
The 32-year-old is still contracted with the Raiders for 2025 and feels like he has plenty more rugby league in his body, with a stint in the Super League with Canberra captain Elliott Whitehead on the cards after his time in the NRL is up.
But Papalii is already thinking about a post-career in disability support.
"It's been a massive drive for me, looking after people that need help in general," he said.
"I know how much work goes into being a parent of someone with a disability. I've witnessed that firsthand."
It's typical of Papalii's character, reckons Stuart.
"He's a huge contributor to people in the community that nobody knows about," he said.
"The amount of children and people that we see here that Papa assists, it again comes back to how genuine and compassionate he is as a person."
