He was capped twice by Finland national football team in 1996–1997.

Born in Kuopio, Nyyssönen played club football in Finland for KuPS, Haka, Hämeenlinna and PP-70, in Belgium for RWD Molenbeek, in Spain for Córdoba, in Scotland for Motherwell (where he scored once against Dundee United),[1] and in Greece for Chania.

[2][3] Since 2016, he was the head coach of various Finnish youth national teams.

[4][5][6][7][8][9] After working for the Football Association of Finland for 15 years, in November 2024 Nyyssönen was appointed by FIFA for their Talent Development Scheme program, as the first Finnish coach.

[10] His elder brother is fellow player Harri Nyyssönen.