As a young Saints fan, Siposs had an unlikely hero - Jason Cripps, who played just 60 games in seven seasons (1996-2002) in a career crippled by hamstring injuries.
Siposs - only the Saints' fifth NAB AFL Rising Star nomination in the past nine seasons - became captivated with Cripps after the tough Saint visited his primary school.
Siposs couldn’t have chosen a more apt role model to draw inspiration from during the early trials of his own football career.
Many factors have also conspired against Siposs making the grade at AFL level but, like Cripps, he battled on and found a way.
In the Beaconsfield under-16s in the Mornington Peninsula league, he was good enough to kick 99 goals in a season, including a bag of 16.4, but initially wasn't invited to train with the Dandenong Stingrays TAC Cup side.
When he got his chance with the Stingrays in 2010, Siposs slotted 34 goals in 15 games.
Injury ruled him out of the draft combine testing process, but his beloved St Kilda turned his dream into reality by snaring him with pick 75 in the 2010 NAB AFL Draft.
Then a quadriceps injury ruined Siposs' first pre-season, but he still managed to play five AFL games when he didn’t expect to play one. His debut season ended prematurely due to shin splints.
Now he's reaping the benefits of an injury-free pre-season in which he continued to, as he described, "build an AFL body", piling on 5kgs of muscle. He aims to add "a couple more" to his 189cm-87kg frame while working towards developing the endurance of skipper Nick Riewoldt (another of his childhood heroes).
Siposs, 19, has played seven games this season and his past three have netted 51 disposals, 20 marks and 5 goals, 5 behinds.
In the Saints' shock 71-point win over Essendon at Etihad Stadium on Saturday night, the talented half-forward had 17 disposals, five inside 50s, kicked two second-term goals (a smart snap followed by a clinical set shot) and set up another. Most striking was his disposal efficiency of 88 percent.
He has always been confident in his goalsense, and now his teammates and coaches share his belief.
"It took a little bit of time to get the boys to trust me in that area but now they tell me, 'Just go back and take your shot'," Sipposs told AFL.com.au.
"And the coaches tell me, 'If you’re in range, just go for it. We trust your ability to put it through.'"
A focus for Siposs has been improving his defensive skills, from which he believes his attacking flair will naturally flow.
He is also learning how to play in the midfield for the first time in his life.
Among those he has been working closely with are specialist coach Aaron Hamill, whose No. 2 he has inherited. He also regards teammate Justin Koschitzke as "a great mentor" who has the knack of putting him at ease.
"It’s definitely a dream come true for me to play with guys I've been watching for a long time, and I'm just trying to make the most of it," he said.
