Tormanen had been playing professionally for Jokerit for four seasons when he was drafted in the 1994 NHL Entry Draft in the eleventh round, 274th overall by the Ottawa Senators of the NHL. After one more season with Jokerit, he signed with the Senators for the 1995–96 season. Tormanen played in 50 games for the Senators, and 22 games with the Prince Edward Island Senators. This was his only season in North America. After the season, he returned to Europe where he returned to Jokerit, and also played for HV71 Jonkoping and Sodertalje SK until retiring after the 2003–04 season. His best season statistically was 1993–94 with Jokerit where he scored 20 goals and 18 assists in 46 games.