Having exclusively played with TPS in Finland, Pärssinen was selected as an alternate captain despite his young age and contributed with a team leading 34 assists and posting 42 points through 55 regular season games.

[1] He topped the league in scoring among under-21 players and in the post-season he helped TPS by contributing with 8 points in 13 games, before falling to a 1–3 finals defeat to Lukko.

He helped TPS return to the Liiga finals, posting a career best 12 points in 18 games before suffering a 1–4 series defeat to Tappara.

At the conclusion of his season with TPS, Pärssinen embarked on his North American career in joining the Predators AHL affiliate, the Milwaukee Admirals, for their Calder Cup playoffs campaign on 5 May 2022, finishing with 1 goal and 3 points through 9 games.

[6] Inserted into the Predators scoring lines, Pärssinen responded with his first multi-goal and 3 points game in just his third appearance, helping Nashville to a 5–4 victory over the New York Islanders on 17 November 2022.