He has also played for the Dallas Stars, Toronto Maple Leafs, Calgary Flames and Anaheim Ducks in the NHL, Lokomotiv Yaroslavl in the KHL, HIFK, Espoo Blues and Kärpät in the SM-liiga and HC Davos in the Swiss National League A.

An accomplished international player, Hagman has represented Finland at three Winter Olympic Games, winning a silver medal in 2006 and bronze at 2010.

[4] Following another 23-point campaign in 2003–04, Hagman signed with HC Davos of the Swiss National League A as the 2004–05 season was wiped out by a labour dispute.

[5] He returned to the Panthers to begin the 2005–06 season, but after 30 games, he was traded to the Dallas Stars in exchange for a seventh-round selection at the 2007 NHL Entry Draft.

[4] An unrestricted free agent following the season, Hagman signed a four-year, US$12 million contract with the Toronto Maple Leafs.

[4] The Calgary Flames acquired Hagman, along with Jamal Mayers, Matt Stajan and Ian White, in exchange for Dion Phaneuf, Fredrik Sjöström and Keith Aulie.

He was subsequently claimed by the Anaheim Ducks on November 14, 2011, with the Flames remaining responsible to pay the other half of his salary for the duration of his contract.

In July 2013, the Finnish SM-liiga club Ässät announced that Hagman had signed for a one-year contract.

[13] An injury to Ville Peltonen shortly before the 2002 Winter Olympics opened up a chance for Hagman to represent the Finnish senior team for the first time.

He played in the 2004 World Cup of Hockey, scoring one goal in five games for Finland, who finished as the tournament runners-up to Canada.

Following a devastating 6–1 loss to the United States in the semi-final, Finland found itself trailing Slovakia by a 3–1 score entering the third period of the bronze medal game.

[18] Hagman announced his engagement to Finnish model and first runner-up of Miss Finland 2003, Piritta Hannula, in Spring 2005.