Dylan Napa’s eyes roll back in his head for a second or two as he declares "if you are not living on the edge you are not having fun".

That was minutes after Queensland's designated enforcer told NRL.com of his deep affection for his 91-year-old grandmother Norma and how she is his greatest fan.

Encapsulated in those two varying sentiments are both sides of the 25-year-old Sydney Roosters and Queensland prop – the ferocious Napa who intimidates on the field and the caring young man who is inspired by his close family.

Napa was in the headlines recently for a tackle gone wrong that broke the jaw of Korbin Sims, a hit for which he later apologised to the Broncos forward.

Maroons chairman of selectors Gene Miles wants a "fired-up" Napa to wreak havoc in game one of this year’s Holden State of Origin series in Melbourne on Wednesday night and that suits the Roosters forward just fine.

"It’s Origin at the end of the day, so if you are not going to go out there and put your body on the line there is no point being out there," Napa told NRL.com.

"It is nice to hear from Gene on that and I’ll be doing all I can for the team. The game we play is rugby league, so if you don’t have fire in you, then you are probably on the wrong field.

"I think I have played 113 NRL games now and I have always been borderline on the edge. What can you do? It is a physical sport.

"Everyone likes to live on the edge. If you are not living on the edge you are not having fun."

Napa's father Stanley played for Norths Devils in Brisbane and for the North Sydney Bears and had a reputation for living on the edge himself.

"They say my old man was a bit physical back in the day, but there is no video footage of it so I don’t know whether I believe him," Napa grinned.

NRL.com rang Stanley to check on his own footy playing style, and how that was reflected in his son.

"I didn’t mind a confrontation," he chuckled.

"I didn’t go backwards. We have very similar styles, but I had more ball skills than Dylan … heaps more.

"Right now I like the fact Dylan is doing his job and all the one percenters people don't want to do."

Stanley summed up Napa's lack of self-preservation on a footy field with an anecdote from his childhood.

"When he was young Dylan loved to ride BMX for hours and hours in the heat and had a high pain threshold as a kid," Stanley said.

"He used to ride his bike off the roof of our house. He’d do somersaults and land on the trampoline and hopefully bounce onto two old mattresses we had either side. If he didn’t hit it square he’d bounce off and land straight on the ground, but he’d dust himself off and say ‘watch while I do this again'."

Stanley also offered up another reason why his son seems to feel no pain.

"I’m a Cook Islander and we always reckon Dylan has a Cook Island head. It’s hard and it can take a fair whack," he grinned.

But the soft heart of his son melts when he speaks about his grandmother Norma.

"My grandma is 91 and is my number one fan,” Napa said.

"She has seen every game that I have played. She is the only grandma I have left and we are close.

"Last year on my debut she got to meet Johnathan Thurston in the sheds and she was rapt. It was a special night. She is a Queensland diehard and used to be a big Broncos fan, but I am hoping I converted her to the Roosters.

"All my family is an inspiration to me. My brother Lewis and his partner Kate just had their first daughter, Grace. I play for them all."

Stanley was not surprised to hear Dylan had a soft spot for Norma.

"They are very close and she has always been a supporter of his from the beginning," he said.

"Every time he comes up to Brisbane he makes sure he goes around to see her."

On Wednesday night Napa will have a date with vocal NSW prop Reagan Campbell-Gillard and company.

At the Maroons launch of the Origin series on Tuesday night, coach Kevin Walters told an anecdote to explain what makes Napa tick and what he was expecting from his enforcer at the MCG.

The game we play is rugby league, so if you don’t have fire in you, then you are probably on the wrong field. Dylan Napa

Queensland were behind 16-6 at half-time in game two last year and Walters said he could feel these "piercing eyes" on him.

He turned around and Napa was staring straight at him. When Walters went over to find out what was the issue, Napa said: "get me back on the field".

With the series on the line, Napa had a blinder in the second half and inspired a famous victory.

"That is when he became a real leader, and we need more of the same," Walters said.

Witness Australia's greatest sporting rivalry when Origin comes to the Melbourne Cricket Ground on Wednesday, June 6. Bronze tickets available from $49 here.