Mayard began his professional career in 2000 with the Montreal Impact of the USL A-League where he had an impressive rookie campaign, recording 4 goals and 2 assists in only 13 games. After having an impressive campaign with the Impact he signed for Dallas Burn of the Major League Soccer. He split the 2002 season between the Dallas Burn and Kansas City Wizards playing only three matches with Dallas. Mayard returned to the A-League to sign with the Toronto Lynx his signing was announced in a press conference on April 30, 2003. He made his debut for the club on May 3, 2003 against Pittsburgh Riverhounds.