It's not easy to go junior for junior with the Panthers.

Penrith's recent dynasty has been built on the back of developing talent – 14 of the club's 17 players for Sunday's grand final against Melbourne came through the Panthers junior pathways.

At the heart of their star-making machine is the club's local junior league, which always seems to be overflowing with future stars.

Of the 68 men's players appearing on grand final day in both the NRL decider and the State Championship, 12 of them are products of the Penrith junior competition.

Melbourne will have just one – Newtown Jets forward Jordin Leiu – which makes his rise to the season's biggest day all the more impressive.

"In Victoria, if you're not at the Storm or a feeder team at the Storm it can be hard to progress after 20s so a lot of boys move to New South Wales or Queensland," Leiu said.

"But it is getting better in Melbourne, they're trying to grow those pathways and build that into the NRL.

"There's still a long way to go, but there's a lot of us floating around trying to make it."

A boyhood Melbourne fan, Leiu played his juniors with the South East Titans, who are based out of Dandenong and produced the first born-and-bred Victorian to play NRL in former Storm and Tigers outside back Mahe Fonua.

Since Fonua's NRL debut in 2012 a handful of other Victorians have cracked the NRL including Richie Kennar, Greg Marzhew, Trent Toelau, Sua Fa'alogo and Fonua Pole.

The trickle from the Aussie rules-dominated state is slow, but steady. 

Leiu himself is no stranger to the Sherrin and played both sports growing up after originally starting with touch rugby.

"But my aggression pushed me into league. I wanted to tackle. Eventually, I started playing AFL as well, for extra cardio," Leiu said.

"I played both until I was 18 or so, then the Storm told me I had to choose because I couldn't risk injury. I chose league and haven't looked back."

Stints with Melbourne, Wests Tigers, Blacktown Workers and North Sydney followed before Leiu found a home at Newtown, a feeder club for the Cronulla Sharks, this year where he's played a crucial role in the Jets charge to the NSW Cup title.

In front of a rowdy crowd of over 10,000 at Parramatta Stadium last Sunday, Newtown withstood a series of desperate, last-minute raids from North Sydney to claim the title.

Leiu himself twisted his way over for a try in the pulsating 28-22 victory over the Bears – who, ironically, act as the Storm's feeder club.

"I'd just come on and Billy Magoulius teed me up a few plays before, he said he'd hit me short so stay alert," Leiu said.

"They got my legs, but I managed to twist and turn my way through. That was a special feeling in itself, I was screaming while I was still on the ground, that's one of the better feelings in life.

"When the Bears knocked on that last time I was on the bench, we all started embracing, the assistant coach said it wasn't over because there was still three seconds left but instinct took over and we all started celebrating. It was such a great feeling."

It earned the Jets their third reserve grade final since 2012 and booked their passage to Stadium Australia on Sunday, where they'll face Queensland Cup champions Norths Devils.

The first game of grand final day has attracted criticism in recent years as both second-tier sides struggle for motivation a week after winning their own grand finals.

But the Jets are locked in. Coach George Ndaira made a point of mentioning the State Championship in the aftermath of the win over the Bears as the Jets look to reclaim the trophy they last won in 2019.

Leiu is certain he won't carry a premiership hangover into Sunday as he proudly represents Victoria on the season's biggest day.

"We wanted to celebrate the win, winning the premiership was our goal all year, but it was a 24 hour thing," Leiu said.

"We got it out of the way, and we earnt it, but there's still one to go and George said that straight after the game, he made sure we kept our footy hats on.

"Our mentality is treating it like a mini-State of Origin. These Queenslanders are coming here and we're going to send them home.

"I've been getting messages from family and friends in Victoria and from all over the place, wishing me luck. I'm sure a lot of them are going to tune in."