McCartin hasn't played in the top flight since July 2018 following a string of concussions that's have kept him sidelined, with the 25-year-old subsequently delisted at the conclusion of the 2019 season.
The former No.1 pick played 35 games for St Kilda, booting 34 goals in a span that included as many as eight head knocks.
After seeing concussions specialists in hope of getting his career back on track, McCartin was signed to Sydney's VFL side ahead of the 2021 season.
The Geelong Falcons product showed some promise in his return to football, however a five-week suspension marred his campaign.
Now, as reported by Nine News Melbourne, McCartin is poised to sign with the Swans's AFL side ahead of next season, with either this month's Rookie Draft or the 2022 Supplementary Selection Period (SSP) seen as potential avenues for the spearhead to make his comeback.
— 9News Melbourne (@9NewsMelb) November 8, 2021
McCartin linked up with his brother Tom in moving to the New South Wales club this season, however a promotion to their AFL list could see the pair play together.
Nine's report suggests McCartin's manager and the Swans have been held talks in regards to a potential lifeline.
With McDonald entering his second season in the AFL and Franklin constantly following precautions measures to remain fit, McCartin firms as a valuable selection should injuries be a thing of the past.
The 2021 Rookie Draft will commence on November 26, while the SSP is set to take place early next year.