UPDATE: AFL's great rugby league experiment, Israel Folau, has announced he will leave the code but says it won't necessarily be to rejoin the NRL.
Hailed as the great convert to the game and the poster boy for the introduction of expansion club Greater Western Sydney, Folau, 23, struggled to adapt.
He played 13 matches in the Giants' inaugural season but rarely showed he had conquered the playing style. He averaged six possessions a match.
"In the end I think the passion wasn't quite there and if I was staying I was cheating myself," Folau said today.
"It has been a great experience and I wouldn't change anything.
"I had to be honest and move forward. I gave it my best shot."
In June 2010, Folau signed what was believed to be a four-year, $4 million deal to join the AFL.
He believed the Giants had a bright future in a market dominated by the rugby codes.
"I think the club has got a great future in western Sydney," Folau said.
"I'm proud of what I did the last two years. Everyone has their different opinions but at the end of the day it's only mine that matters."
NRL struggler Parramatta have already shown interest in luring Folau, who is originally from Sydney, of Tongan parents. Folau played two seasons for Melbourne Storm and two for Brisbane Broncos in the NRL before his defection to the AFL.
He even said he was open to jumping to a third code of football - rugby union.
"At this stage I've had no discussions with any clubs at all and I'll leave it up to my management to control that stuff," Folau said.
“My future at the moment is uncertain. I still don't know what to do.”
His departure fuels speculation that the Giants could recruit former Adelaide key forward Kurt Tippett through the national or pre-season drafts.
AFL chief executive Andrew Demetriou paid tribute to Folau's courage to swap codes.
"Israel Folau has been a terrific ambassador for our game in the past two years and his courageous decision to give AFL football a go has helped inspire many children, particularly in NSW and Queensland, to play and watch Australian football," Demetriou said.
"Naturally we are sad to see Israel leave the AFL community but we understand and respect his decision. He goes with our blessing."
GWS have the No.1 picks in the two drafts and, with no Folau, they have ample room in their salary cap to accommodate Tippett's hefty asking price.
Adelaide are the subject of a major AFL investigation over draft tampering and salary cap breaches.
The investigation relates to Tippett's last contract with the Crows, signed in 2009.
The Crows face massive penalties if the AFL rules against them.
Tippett wants to play for Sydney, but the Swans were unable to negotiate a deal with Adelaide during the trade period.