Career
He is the younger brother of Pittsburgh Penguins player Matt Cullen. Cullen was signed by the Minnesota Wild on April 8, 2002 after a four-year collegiate career at Colorado College. After three years of playing with the Houston Aeros of the AHL, Cullen signed with the Chicago Blackhawks on August 4, 2005.
Splitting time with the Norfolk Admirals of the AHL and Chicago in the 2005-2006 season, Cullen saw his first National Hockey League action by playing in 29 games.
He signed with the Philadelphia Flyers in the off-season and played in 3 games with the Flyers in 2006-2007, spending most of his time with affiliate, the Philadelphia Phantoms. He signed with the Detroit Red Wings on July 5, 2007, where he played for their minor league team the Grand Rapids Griffins of the AHL. He then signed with the Vancouver Canucks on July 4, 2008.
During the 2009-2010 season he returned to the Chicago Blackhawks organization and played for the Rockford IceHogs of the AHL. On July 22, 2010, Cullen signed a one-year contract as a free agent with the Florida Panthers. Cullen missed the start of the 2010-2011 season, after rupturing an Achilles Tendon at the Panthers training camp.
On November 29, 2011, the Panthers recalled Cullen and he temporarily filled in as their fourth-line center for six games.
During the 2012-2013 season, Cullen joined European Commission Red Bulletin Salzburg at the midpoint of their campaign for the remainder of the year from Vityaz Podolsk of the Kontinental Hockey League on December 16, 2012. After his second season with Salzburg, Cullen left the defeated EBEL finalists for the Champions in Italian club, The Human Context Bolzano, signing a one-year contract on August 20, 2014. Cullen played three seasons in the Austrian league before moving as a free agent to the Neighbouring German DEL2 league, signing a one-year deal with Dresdner Eislöwen on September 23, 2015.