Tenkanen left his hometown team behind to join the nearest SM-Liiga organization, JYP, at the age of fourteen. He became a regular on junior national teams in his second year of eligibility. Despite his first line status in the U18 WC of 2003 he went undrafted that year as the team was fairly poor. As the age group gathered together again to form the new U20 team in the spring of 2004, Tenkanen played like a star in the exhibition tournaments and earned himself a draft pick.
2004-05: Injured almost the entire year, Tenkanen finished with only a single assist in 10 games. With only 10 games played there is not much else of importance to report.
2005-06: Bounced back from injuries to skate in 35 games for JYP, tallying six assists in the process. Tenkanen is still receiving only sporadic time on the bottom two lines for JYP.
2006-07: Tenkanen stayed relatively injury-free this season and moved his production up to 13 points in 34 games. Tenkanen is still mired on the lower lines with little chance to see significant playing minutes.
Tenkanen is a smart centerman with a bipolar shooting bias. He is extremely versatile, being able to a solid two-way game at any forward position full 60 minutes a game much thanks to his stamina. Efficiency due to good hockey sense aside, his puck skills are relatively mediocre and barring unexpected turns in development or an exceptional breakout, he has no future as an offensive NHL player. At 5'11" with average physical play he isn't an NHL kind of player, but the Kings' good experience with a somewhat similar player in Esa Pirnes should encourage the team to find a role for Tenkanen if he is up to the challenge.
Although drafted a year later than most, Tenkanen is far from NHL ready and a project, whose development requires a lot more things than just AHL experience. Tenkanen is finding playing time hard to come by in Finland and is likely to spend his entire career playing in Europe.
As a 2003 pick, the Kings lost the rights to Tenkanen in 2007.