After three years of playing with the Houston Aeros of the American Hockey League (AHL), Cullen signed with the Chicago Blackhawks on August 4, 2005.

Splitting time with the Norfolk Admirals of the AHL and Chicago in the 2005–06 season, Cullen saw his first NHL action by playing in 29 games.

Cullen signed with the Detroit Red Wings on July 5, 2007, playing for their minor league team, the Grand Rapids Griffins of the AHL.

During the 2012–13 season, Cullen joined EC Red Bull 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.

[3] After his second season with Salzburg, Cullen left the defeated EBEL finalists for the Champions in Italian club, HC Bolzano, signing a one-year contract on August 20, 2014.