The 21-year-old informed the Suns of his intention to leave late last week, and executed a formal release from his 2016 contract.
"I have been weighing this up for a while and I've thought about it a lot over the break," Boston said.
"Although it’s a really hard decision, I know it's the right decision for me.
"AFL football is a lifestyle, not a job. At the elite level you've got to live football 24/7.
"If you can’t live your entire life with the necessary commitment and discipline you won’t and can't be elite.
"At the moment I simply don't have the passion required to play at the elite level, and don’t want to take a spot on the Suns list that can be given to somebody else."