The Glory confirmed on Thursday Castro wouldn't be a part of their squad for the 2021-22 campaign, ending a successful six-year stint in Western Australia for the 39-year-old.

Castro was twice named in the PFA Team of the Year and won the Johnny Warren Medal during his time at Perth, and was a key part of the club's 2019 premiership-winning team.

The club's signing of ex-England international Daniel Sturridge all but ensured Castro's exit.

While he is finished with the Glory, Castro released a statement via the PFA confirming he had no intention to hang up his boots.

"I wish it did not end in this way or in these circumstances, but that is football sometimes," Castro said.

"Although, I'm not hanging up my boots yet.

"I promised myself the day that I'm going to step away for the game that I love, it would be on my own terms ... so I will stick with it. The journey continues."

Castro took time to thank the city of Perth for "looking after me and my family" but seemed to hint that the decision to leave the Glory was more to do with the club than with his own desires.

"To the sports directors, CEOs and the owner of this club, we did not always agree with everything, but what happens along the way makes us who we are," he said.

"I'm thankful to everyone for giving me the chance to play in the A-League.

"I don't not hold any grudge with anyone, I have made peace with everything."

Owner Tony Sage said earlier this month that Perth had taken the option to sign former Liverpool striker Sturridge after not hearing from Castro about whether he would be returning for the 2021-22 season.

In the club statement released on Thursday, Sage paid homage to the playmaker who scored 49 goals in 136 A-League appearances for the Glory.

"In my opinion, he has been the greatest visa player to visit Australia," Sage said.

"I am personally very sad that he is leaving and wish him and his family all the best in their future."

Where Castro will continue his career, and whether it will be in Australia or overseas, remains unclear.

Australian Associated Press