The native of Helsinki, Finland played several years with the Jokerit junior and senior squads as well as Reipas Lahti. In 1992 the Calgary Flames at the NHL Entry Draft took him 102nd overall. Beginning in 1994-95, the burly rearguard spent most of his first four seasons in North America with the AHL's Saint John Flames.
In January, 1999 Helenius was traded to the Tampa Bay Lightning but only made it into four games with his new club. Two months after he was acquired, Tampa sent him to the Colorado Avalanche. Helenius played 33 NHL games the next year in Colorado and toiled briefly for the Hershey Bears of the AHL. After signing as a free agent with the Dallas Stars in July 2000, Helenius found his niche on one of the NHL's most defence-oriented clubs. He averaged nearly 11 minutes in 57 games while taking the body and playing within his means.
Helenius spent the better part of three seasons with the Stars oranization before joining the Chicago Blackhawks in 2002-03.
