Vergara retired as a FIFA Assistant Referee effective November 12, 2011.  Vergara spent 19 years on the FIFA list and was involved in 11 FIFA competitions. Three of those competitions were FIFA World Cups (2002, 2006 and 2010). Vergara claimed the record for most World Cup games as a referee/assistant referee at 14 when he took the field July 10, 2010 in the third-place play-off match between Uruguay and Germany at Port Elizabeth Stadium. His amazing World Cup appointments included two 3rd placed matches (2002 & 2010) as well as the Germany - Italy Semi-Final in 2006.

In total, Vergara officiated nearly 150 international matches involving Clubs and Nationals Teams playing at the highest competitions in the world. His list of accomplishments include Six CONCACAF Gold Cups (three Finals), the 2004 Olympic Games (Semi-Final), the 2009 FIFA Confederations Cup (Fifth official on final), two FIFA Club World Cups (finals in 2005 & 2009) as well as two FIFA U-20 World Youth Championship (ARG-FRA QF) and two FIFA U17 World Championships (BRA-ARG semi in 1995, 3rd place match in 1993).

In 2012, Vergara was appointed by FIFA to its Referees' Committee as a Development Member. He was selected as a member of the Canadian Soccer Hall of Fame in 2014.