And despite the obvious comparisons being drawn, he's not a clone of former champion Alex Rance.

But the emerging star, who turns 21 on Friday, is already a crucial piece of the Tigers' unusual eight-man defensive puzzle.

They've just got to iron out a few kinks.

"He's had moments where he's done unbelievable things," Richmond defender Nick Vlastuin told AAP.

"Then he's had moments where he probably wishes he could take them back, kicked it straight up the guts a couple of times and stuff like that.

"It's been fun along the way and he's just so athletic, you can always get some highlights out of him."

Balta, already a 194cm and 100kg phenomenon, will be the youngest player in Saturday night's grand final against Geelong and is the only Tiger still chasing his first premiership.

He arrived on the AFL scene in round one last year in what turned out to be Rance's final game, when the five-time All-Australian was cut down by a knee injury.

It became a changing of the guard and the comparisons were inevitable as Balta worked his way into the vacant position.

They were validated by Richmond coach Damien Hardwick's declaration earlier this year that Balta is a "young Alex Rance".

But fellow key defender David Astbury notes some clear differences and believes the 29-gamer is poised to forge his own identity out of the shadow of one of the modern game's great backmen.

"Noah's marginally more athletic, whereas Rancey would just beat you up for days with discipline and stubbornness," Astbury told AAP.

"Noah is just a young bloke trying to find his way, but by goodness he's got some potential and we want to maximise that.

"At different stages throughout games he shows his physical attributes and they're just extraordinary.

"He's still got quite a ceiling to reach and right now, even though he's playing some really good footy, he's still a fair way off it."

Balta played 13 games last year - reviewing tape of each one of them with Rance by his side offering guidance - but missed selection for the successful finals series.

His true emergence came this year when Astbury spent almost three months on the sidelines with a knee injury.

Balta stepped up and blunted some of the game's best key forwards, including Charlie Dixon, Jeremy Cameron, Matt Taberner and Max King.

"For a guy his age he's probably as (physically) mature and strong as anyone I've ever seen really," Richmond defensive coach Justin Leppitsch said.

"He's got a lot of upside and there's a long way to go in his career and a lot of achievements to be had, but for a guy his age to be able to play on mature guys like Charlie Dixon and match them in that strength battle is a really good sign.

"Where can Noah improve? Like anything in time, maturity and decision-making, all those sorts of things. They're things you get better at the more you do."

In round 17, when Richmond last met Geelong and scored a convincing 26-point win, Balta limited likely grand final opponent Tom Hawkins to one goal despite his relative inexperience against the 14-season veteran.

"He's a great player and he's got a lot of talent and attributes," Coleman medallist Hawkins said.

"In the past I've played on Alex Rance and David Astbury ... but Noah's a great athlete and from what I've seen of him he reads the game pretty well."

Astbury's return to action late this season, coupled with ruckman Ivan Soldo's knee injury, has seen Hardwick and Leppitsch tweak their defensive approach yet again as part of an ongoing evolution.

Selecting eight defenders in the best 22 has allowed Astbury to offer Toby Nankervis some relief by pinch-hitting in the ruck.

Balta, Astbury, Vlastuin, Dylan Grimes, Nathan Broad, Jayden Short, Bachar Houli and Liam Baker will all roll through the back line during the grand final.

"Change is good sometimes and over the last couple of years in the absence of Rancey, who was a once-in-a-generation player, the system has still worked," Astbury said.

"Noah's done such a remarkable job and I'm enormously proud of that man.

"He's really invested in the culture and what we believe in here and he's also really invested in his own development, and that's why we're seeing such rapid growth."

Australian Associated Press