2003–2007 The American national team, the
USA Eagles, gave him a route into international rugby union. Hercus made his debut for the U.S. national team in 2002. Hercus played in the
2003 Rugby World Cup, scoring 51 points for the Eagles. Hercus played at
Sale Sharks for two seasons as
Charlie Hodgson's understudy before moving to
Llanelli Scarlets. Hercus secured a starting position at fly-half during the season, which he maintained in the 2006
Powergen Cup final (which saw the Scarlets lose to
London Wasps 26–10). Hercus moved to the
Newport Gwent Dragons in the summer of 2006 after it was announced that Welsh international fly-half
Stephen Jones was to move to the Scarlets. Also, in 2006, Hercus was invited to play for the prestigious
Barbarians FC.
2007–2010 Hercus captained the Eagles in their 2006 qualifying matches against Uruguay for the 2007 Rugby World Cup. He returned to the US for the start of the 2007
U.S. Rugby Super League season, where he played for Belmont Shore and was in the US Falcons NA4 squad. Hercus started all four matches for the U.S. in the
2007 Rugby World Cup. At the start of 2008, Hercus signed a contract to play for Japanese club
IBM Big Blue. In 2009, after just one season, Hercus signed with the Australian club
Sunshine Coast Stingrays, where he was the club's leading scorer in limited action. Hercus played with the USA Eagles during the 2009 summer internationals, including the Eagles against Canada and Uruguay in the
2011 Rugby World Cup qualifying matches. These qualifying matches in 2009 were Hercus's last matches for the U.S. national team. In 2010, Hercus returned to Australia and his junior club, the Gordon Highlanders, to compete in the
Shute Shield. To start the season, he was named Gordon's captain but saw limited action due to injury. By midseason, rumors began to leak out that he had retired or intended to retire from both international and club rugby due to persistent reoccurring injuries. Although no official announcement has ever been made, he has been presumed retired since summer 2010. ==Personal life==