Sparks played minor league hockey with Chicago Mission of the Tier 3 Elite Hockey League, before joining the Guelph Storm of the Ontario Hockey League (OHL) in 2010. He was drafted by the club in the eighth round, 160th overall in the 2009 OHL Priority Selection. Sparks made 19 appearances for the Storm, going 8–6–1 for a .890 save percentage, playing well enough to be picked by the Toronto Maple Leafs 190th overall in the 2011 NHL Entry Draft. Sparks would spend the next two seasons with the Storm, briefly playing in three games for the Maple Leafs' American Hockey League (AHL) affiliate, the Toronto Marlies, at the end of the 2012–13 season. In 2013, Sparks represented the United States and won gold at the 2013 World Junior Ice Hockey Championship in Russia. The next year, Sparks would split time between the Marlies and the Orlando Solar Bears of the ECHL.