GWS has shown absolute faith in the All Australian's promise to improve his on-field behaviour by signing him to a six-year extension, avoiding another protracted Josh Kelly saga in the process by securing Greene's prized signature more than two weeks out from the Giants' round one opener against the Western Bulldogs.

The classy 24-year-old kicked 45 goals in 19 matches last year, but missed four games through two suspensions and was fined for three further incidents by the Match Review Panel. That followed his All Australian season in 2016 when he also won the Kevin Sheedy Medal as the club's best and fairest player.

He's battled a toe injury this preseason, but hopes to play in Friday's clash with the Sydney Swans at Blacktown.

"The Giants have shown massive faith in me throughout my career in giving me a few chances and I was more than happy to repay the favour," Greene said.

"It's up to me to rectify [ill discipline]. I don't think it'll be any issue going forward - I put a few things in place last year.

"I had no hesitations in signing a long term deal because this is where my home is and this is where I've made all my best mates coming through the ranks. I didn't contemplate anything else but staying here."

In signing Greene so early this year the Giants have staved off what would have been a frenzied marketplace chasing the superstar's signature for 2019 and beyond.

It took until just before the preliminary final last season to secure Josh Kelly for a further two years, and the club spent all of entire 2017 swatting away questions about the youngster's future.

"When I got approached about a longer term deal I was very open to it and extremely excited to sign," Greene said.

"It saves a lot of lying to the media I guess. I saw what happened with Josh Kelly last year, he copped it so I wasn't interested in that.

"Everyone's got a strong bond here. We've shown we've come a long way and we've got to two prelims in a row now but we're not happy there we want to go further and this gives me a big opportunity to do that."

Greene said his disciplinary record wasn't mentioned during contract negotiations, and chief executive Dave Matthews had the club had no hesitation in re-signing the fiery forward.

"Any player with his level of talent is going to face some challenges from defenders on a week to week basis," Matthews said.

"He, by his own acknowledgement, from time to time he's let that get the better of him. That's the trick of any key forward to be able to work out ways to cope with that.

"He's a very mentally tough individual so I'm sure that's something he'll continue to get on top of. When you've got confidence in the player and the person then it makes sense to both parties."

Greene was drafted to the club with pick number 11 in 2011 having emerged as one of the country's best young midfielders during his final school year.

He was ultimately thrown forward by the Giants who had a plethora of quality midfielders at their disposal, and the move has benefited both club and player.

AFL talent manager Kevin Sheehan says Greene's aggression has helped him become a superstar of the game.

"Grunt, or true grit, you can call it a few other things...it's a hard edge, and he loves physical contact, he thrives on it," Sheehan said.

"He plays on the edge. He mightn't say much but geez you can see it in their intensity around the contest.

"Some of the smaller blokes do that, it's like they've got a chip on their shoulder, they haven't really, but they're just so angry they don't want anyone to get the bloody ball off them.

"That separates average players from guys that can end up champion players, that sort of an attitude."