"When the opportunity to join the Bulls arrived, it was one I couldn't turn down," Mariappa said.
"It's an exciting new challenge for me in my career and that for me is what I thrive off.
"I'm hungry to achieve great things with the club and create new memories with the team and the fans."
Coach Ante Milicic added: "I'm thrilled that the club has been able to secure a player of Adrian's quality and experience.
"Although he has never played A-League before, I'm most certain he will make a seamless adjustment given the career he has had so far."
Need a VPN? Or seeking to switch? Then support Tribal Football by clicking here to sign up with our official partners NordVPN. Not only will you receive the best VPN experience, but also great discounts by signing up via Tribal Football. Thanks for your support!