After playing for the Belmont Steelers, a Western Australianfeeder club for the North Queensland Cowboys, Petersen was called up to the NRL in 2002. Petersen moved from North Queensland to the Parramatta Eels half way through 2002 and played for the Eels with some success until 2006. Early in his career at the Eels, Petersen was at the centre of a spiteful match against the Brisbane Broncos at Parramatta Stadium after Allan Langer appeared to drop his knees into Petersen, some members of the crowd later throwing bottles at Broncos players. Petersen equalled the club try-scoring record for one match during the 2003 round 12 clash against the South Sydney Rabbitohs. Scoring four tries in the one game, he was the first Parramatta player to have done so since 1988. In 2005, Petersen made 13 appearances for Parramatta as the club won the Minor Premiership but he did not feature in any of the finals matches. Parramatta care-taker coach, Jason Taylor, dropped Petersen from the first-grade roster when he took over coaching duties in May, 2006, and demoted the under-performing winger to the Premier League, where he spent the rest of the season. "Side-Show Bob" joined the Titans in 2007 for their first year in the NRL. He performed well and was well known as "Sideshow Bob" due to his thick, curly hair. He ended the season with the most tries scored, shared with Mat Rogers. At the end of 2007 he played for America. In May, 2008, he was given an immediate release to join Super League side Wakefield Trinity Wildcats. As of 2012, he currently plays rugby league in Gympie.
Griffith Uni Colleges Knights
Since 2017, Petersen has been a player and specialist backs Coach for the Griffith Uni Colleges Knights Rugby Union Club. Petersen helped the Knights to their Second Gold Coast District Rugby Union Premiership in 2018 in his position of Backs Coach. Club CaptainShaun Cole was quoted as saying "Without Petersens help with our defensive patterns the club wouldn't be where it is today" He has since re-signed for the 2019 season.
Representative career
In 2004, Petersen played a game for the United States against Australia in an exhibition match in Philadelphia, qualifying for the American side under the parent rule. In 2007, Petersen was named as captain of the USA team for their 2008 Rugby League World Cup qualifying match against Samoa. He was awarded Man of the Match for the game, but could not stop the USA falling to defeat. Petersen made a comeback in 2013, being named as part of the USA squad for the 2013 Rugby League World Cup. He scored a try in their opening win over the Cook Islands.
