Chief executive Peter Filopoulos stated that negotiations with Risdon came to an end on Wednesday, with the fullback informing the club of his intentions to move on.
"Despite presenting a very strong offer to Josh and his management, we've been advised today that he won't be renewing his contract for season 2017-2018 and beyond." Filopoulos said in a statement on Glory's website.
"We understand Josh is keen to explore life outside of Western Australia, and while we respect his decision, we are extremely disappointed he won't be wearing the purple kit after season 2016-2017."
Risdon has spent his entire professional career with Perth, making his debut in 2010 as an 18 year-old and has since become the most capped player in club history having made 127 appearances.
Given his long history at the club, the fullback said it was a tough decision to make to leave the team.
"This has not been an easy decision. I feel the time is right for me to explore a new adventure and grow in a different environment and move out of my comfort zone in Western Australia," Risdon said.
"I'm a WA boy through and th4rough and hopefully I'll be back one day to play in front of my family and friends. I'd like to thank the fans who've embraced me along the way and I'll always be grateful for their support."
