Mansell spent his formative years in the southern Launceston suburb of
Prospect, enjoying Prospect Hawks AFL Auskick, played junior football for the
North Launceston Football Club and attended high school at Prospect's St Patrick's College. As a junior, Mansell was a member of the Tasmanian State Academy and joined the Next Generation Academy as a 16 year old in the program's inaugural 2016 intake. He trained with 's AFL squad regularly as part of the program. In 2017 Mansell played state representative football with the
Tassie Mariners . In the same year, he made his senior
Tasmanian State League debut with North Launceston and was a member of the club's premiership winning side in their grand final win over
Laurderdale that September. Mansell was eventually selected to represent Tasmania as a member of
The Allies side at the
2018 AFL Under 18 Championships, but missed two games as a result of the earlier quad injury. At the end of the season, Mansell was invited to attend the Tasmanian AFL draft combine. After going undrafted in both the 2018 national and rookie drafts, Mansell was eligible to be signed by as a category B rookie under Next Generation Academy rules, but was ultimately overlooked. As an overage player in 2019, Mansell joined the newly re-formed
Tasmania Devils side in the Victorian-based
NAB League Boys competition, where he placed fourth in the club's best and fairest. He played state-league football once again for North Launceston that season, winning a third-straight TSL premiership. Mansell was once again eligible to be drafted in 2019 (including with priority academy access by North Melbourne), but was again looked over at the national and rookie drafts. Mansell relocated to Adelaide in 2020, playing senior
SANFL football with
Woodville-West Torrens. He became a key player across the course of the season and featured in a finals series that included a premiership. He contributed a strong 19 disposals, eight marks and five tackles while playing as a half-back in the club's grand final victory over North Adelaide. Despite his strong season, Mansell was again overlooked by AFL clubs at the 2020 national and rookie drafts.
Junior statistics NAB League Boys Under 18 National Championships ==AFL career==