During his playing career, Wallenius made 190 appearances and scored two goals in top-tier Veikkausliiga for Inter Turku and Jaro.
[1] He also played for Turun Toverit and VG-62 in lower divisions.
For the 2028 season, he was named the head coach of Sinimustat, the reserve team of Inter Turku.
During 2008–2016, Wallenius worked as an assistant coach of the club's first team,[2][3] and in 2016 after the departure of Job Dragtsma, he was named an interim manager.
[6] His father Arto Wallenius is a former long-time kit manager of Inter Turku.