After a year of minor hockey with the Chateauguay Patriotes, Sauvé was selected first overall by the Saint John Sea Dogs in the 2006 Quebec Major Junior Hockey League (QMJHL) Entry Draft. He began his junior career with the Sea Dogs the following season in 2006–07, recording two goals and 15 points over 60 games as a rookie. After his first QMJHL season had ended, Sauvé was named to Canada's national team for the 2007 IIHF World U18 Championships, held in Rauma and Tampere, Finland. He recorded one assist over six games, as Canada was defeated in the bronze medal game by Sweden.