MIDFIELDER Rhys Palmer has left Fremantle and signed a four-year deal with new franchise Greater Western Sydney in an effort to further his playing opportunities.

The 2008 NAB AFL Rising Star, who has played 54 games in four seasons, advised Fremantle on Tuesday morning that he would not seek a new contract for 2012, confirming his deal with GWS that afternoon.

Football manager Chris Bond said Fremantle was disappointed to lose Palmer, who was recruited with pick No.7 in the 2007 NAB AFL Draft, but the club understood the new AFL landscape.

"We wish Rhys all the best for the future," Bond said. "Given Rhys decision to leave, our role is to now seek the best possible outcome for the Fremantle Football Club."

Palmer told his manager Colin Young's player management website that his move was influenced by the opportunity to spend more time playing as a midfielder.  

The 22-year-old, who had a knee reconstruction in 2009 and has since struggled to rediscover his best form, has been used regularly as a high forward this season, averaging 15 disposals in 15 games.

"It was the hardest decision that I have ever had to make," Palmer said. "The relationship with my mates and the staff at Fremantle is very strong.

"However, the opportunity to play in the midfield that is being given to me at GWS is what I trained for all through my football career."

Fremantle's draft compensation for losing an uncontracted player to the expansion club will be decided based partly on the financial terms of Palmer's contract with GWS.

It is a deal that Young's website described as a "massive package".

Asked on radio station 6PR on Monday night what his gut feeling was on Palmer's future, Fremantle coach Mark Harvey said: "I'm fairly well connected to GWS, so you can work it out from there".   

The coach said no other Fremantle players had come to the club requesting trades, but opposition players had expressed interest in moving to the port club though their management.    

"Particularly guys from WA in and around those eastern states clubs, sometimes they want to come home for different reasons," he said.

"Some players want to come to Fremantle for other reasons. It'll all come out leading into trade week.

"We'll certainly consider the approach."

Harvey also said that he had not been told by contracted ruckman Jon Griffin, who joined the club at the end of last season, that he wanted to return to an Adelaide-based club.

Nathan Schmook covers Fremantle news for afl.com.au. Follow him on Twitter: @AFL_NSchmook