Treloar becomes the first of the Giants' inaugural core of youngsters to reach the century mark and although he's no longer based in Sydney's west, Treloar was traded to Collingwood last season, the milestone is no less significant.

The 23-year-old has only missed a handful of games through five seasons of AFL footy, and proven himself one of the most talented and resilient of the maiden clutch of youngsters recruited to GWS.

Such was his early potential, Treloar didn't even go through the draft. He and ex-Giants teammate Dylan Shiel were signed in 2010 as underage recruits, GWS at the time having early access to the 2011 draft pool as part of the list concessions used to build the new club.

Kevin Sheedy, early Giants figurehead and Treloar's first AFL coach, always felt the Victorian native would succeed in the AFL.

"He just had talent and ability to read play and the ball, and he's probably a boy that's very, very confident in believing in himself," Sheedy said.

"He would improve, he would grow, I like players that you think will grow into a career, he was one of those."

Of the original group of GWS youngsters, Toby Greene is next in line to bring up 100 games.

He sits on 94, and can rack up the century this year if GWS play every week of the play-offs and make it through to the grand final.

Jeremy Cameron and Devon Smith have both played 89 AFL games, although Smith would've been much closer to triple figures had he not missed half of this season with a knee injury.

Sheedy was just one piece of the early GWS jigsaw responsible for developing the club's early riches of young talent.

Stephen Silvagni, Neville Stibbard and Sam Sheedy were heavily involved in bringing the youngsters to the club while the likes of Craig Lambert and Mark Williams were tasked with mentoring the AFL's youngest playing roster.

It was a punishing environment early on with the Giants managing just three wins in their first two seasons, but those days are almost a distant memory now with GWS sitting fifth in the AFL and preparing for a maiden finals campaign.

"Many people put into the development of that squad and that's why they're probably going quite well," Sheedy said.

"We didn't actually push them that hard early, we kept them them fresh and vibrant.

"The most important thing to do is never take the soul off a kid when they get smashed in their early games.

"It's always about keeping them up and working through different phases of their young individual selves, give them belief and give them confidence."

Treloar has certainly taken that belief and confidence to Collingwood where he's arguably been the struggling club's best player this year.

Magpies coach Nathan Buckley said his efforts on and off the field have been first class.

"What the supporters would see on field is only the tip of the iceberg," Buckley said.

"His attitude and his professionalism in the way that he goes about things, every moment of every day since he's been at the footy club, he's dragging a lot of young guys along with him.

"He's a winner, he's a professional and we are fortunate to have him in the club."