Career
He is currently playing for Jokerit of the Kontinental Hockey League (KHL). Helenius was selected 15th overall in the 2006 National Hockey League Entry Draft by the Tampa Bay Lightning, partly on the strength of his silver-medal-winning performance for the Finnish national men"s hockey team in the 2006 under-18 World Junior Championships. He played for Ilves during the 2006-2007 season but due to a shoulder injury only played four games.
The Seattle Thunderbirds selected Helenius with the 46th overall selection in the 2007 Canadian Hockey League Import Draft.
Helenius joined the Thunderbirds roster at the start of the 2007–2008 season. In December 2007, Helenius was selected as goalie for the Finnish World Junior Team in the 2008 IIHF World Junior Championships.
On October 17, 2008, Helenius was assigned to the Augusta Lynx of the ECHL. He played first National Hockey League game on January 30, 2009 against the Philadelphia Flyers. In 2009 he went on to play for Södertälje Saskatchewan after playing just 10 game for the Norfolk Admirals.
After a great season in Finland, Steve Yzerman, General Manager of the Tampa Bay Lightning, expressed interest in bringing Helenius back to North America, as he was still a Lightning prospect.
On June 13, 2012, Helenius signed a two-year contract with the Lightning. In the midst of the 2013-2014 season, with Helenius unable to make an impact up the Lightning"s depth chart, on February 22, 2014, he was placed on $125 unconditional waivers, which would bring his contract with the Tampa Bay Lightning to an mutual education On April 14, 2014, Helenius agreed to a multi-year contract with Finnish club Jokerit of the KHL.