Earlier this week, 2020 Veikkausliiga champions HJK announced that an agreement had been reached with Untersee for the Johannesburg-born former Switzerland youth international to move to Finland for the upcoming 2021 campaign.
"HJK and Joel Untersee, 26, have entered into an agreement covering the period for 2021. The agreement was signed yesterday [Monday] shortly after the medical examinations had been completed," the club announced on its official website, as translated.
Untersee started his career at the FC Zurich academy in 2008 before joining Juventus two years later. He later represented the Bianconeri's reserve side and had spells in the Italian Serie B with the Brescia and Empoli, before joining FC Lugano last year.
Untersee was among the foreign-based players who were named in the provisional 30-man squad for South Africa's 2019 Africa Cup of Nations squad, but was ultimately not selected as part of Stuart Baxter's travelling party for the tournament.
He is the latest South African footballer to move to Finland in recent times after former SuperSport United striker Darren Smith (24) joined rivals FC Honka in December, following a season in the second division where he won the Golden Boot and Player of the Season awards with Ekenas IF.