The 36-year-old former A-League player of the year has extended his spell in the West having chalked up over 90 Hyundai A-League appearances and 38 goals since arriving in 2015.

"I have had a fantastic emotional relationship with the members and fans since the first day I arrived here and I want to keep that love story with the fans going.

"Now I want to help the club add another trophy to the Premiers' Plate.

"With Tony Popovic here, the future of the club is in the best hands possible and I'm so grateful for all the help that he has provided me with this year," he said in a statement today. 

Castro played almost 275 times in Spain across all competitions including La Liga, where he played for Getafe and Sporting Gijon. 

Glory Football Director and former Leeds United midfielder Jacob Burns said Castro is already a Glory great. 

“Diego has been one of the greatest players that this club and the Hyundai A-League has seen,” he said.

“His legacy is already assured, but we all hope that he can further embellish that legacy by helping the club complete the Championship-Premiership double this season and secure more silverware in the seasons to come."

Glory will play in the A-League finals next month, aiming for a first-ever Championship trophy following their Premiership title win confirmed last week.