Del Piero hangs up his Sydney boots
Del Piero took to his official website to detail his decision and say he was happy to explore new opportunities with the club.
"Australia, the moment has arrived to say arrivederci," Del Piero wrote.
"My adventure with Sydney FC is about to be concluded, and, even if it makes me rather sad, because I have had wonderful time here, I have communicated my decision to the club.
"I'm really grateful for the last two years and for the club’s request for me to remain and with whom, I am happy to explore new opportunities to continue our relationship.
"It hasn't been an easy choice, also because my life on and off the pitch has been fantastic, my family and I have really enjoyed these two wonderful years. Australia will remain in our hearts forever."
Club chairman Scott Barlow said the 39-year-old made an unrivalled contribution to Australian football and growing the game.
And after two seasons, the club was keen to continue the relationship with the football legend in some capacity.
Barlow said: “Two years ago Sydney FC signed one of the greatest players to have ever worn a football shirt, Alessandro Del Piero.
"At the time, if you had said Del Piero would be playing in Australia, few people would have believed it possible.
"His signing was the biggest in Australian football history and it lifted Sydney FC and the A-League onto the world stage."
Barlow highlighted the Italian's immense impact on the club.
“Together we have achieved a lot and Sydney FC has grown in every way, with record crowds and memberships and huge interest in our club both domestically and internationally,' he said.
"There is no doubt that Alessandro’s contribution has laid the foundations for a lasting legacy and he has inspired a whole new generation of Sydney FC football fans and future players,.
"The next generation of Sydney FC stars will be the kids who came along with their parents to watch Del Piero on the pitch in Sydney."
Barlow said it was Del Piero's decision to call time on his playing days with Sydney.
"While it would have been fantastic to see Alessandro remain in Sky Blue, ultimately this has been his decision,” he said.
Sydney and Del Piero are continuing discussions about his potential new role within the club.
Barlow added: “Today is bitter-sweet.
"While we would have liked to see Alessandro remain at Sydney, his decision now allows us to further our discussions about some exciting new opportunities for our ongoing relationship and to build on the legacy that has been started.
“On behalf of everyone at Sydney FC I would like to say thank you to Alessandro for the enormous contribution he has made to our club over the last two years.
“It has been a pleasure and a privilege to have him at our club and we look forward to seeing him in the near future when he is next back in Sydney."
Del Piero wrote of his fondness for Australia: "I've come to know and love this fabulous country, even though I have lived on the opposite side of the world, right from the first day, you made me feel at home.
"For this I cannot be more grateful to anyone, above all to my supporters, not only those of Sydney FC, all of whom have always shown me their love and respect, in all the cities of Australia.
"Together we have managed to do so much, it's enough just to think about the training camp in Jesolo, the first experience of this kind for an Australian team; this is an excellent point from which to make a new start, and even more so the support of our Sky Blues fans, constantly growing and ever closer to the team, so much so that in these two seasons the record attendances for the stadium have been rewritten."
"Now is the right moment to simply say thank you to everyone."
Del Piero said his greatest satisfaction was the rapid growth of Australian football.
He said he would remain a "bit Australian" and continue to be close to the local game, particularly in his role as ambassador of the 2015 AFC Asian Cup. And signed off with "see ya mates - with love, Ale".