Makarov played major junior hockey with both the Lewiston Maineiacs of the QMJHL and the Saskatoon Blades of the WHL. He also played with the Russia men's national junior ice hockey team at both the 2012 and 2013 World Junior Ice Hockey Championships, winning silver and bronze respectively. On 14 September 2012, the Buffalo Sabres of the National Hockey League (NHL) signed Makarov as an undrafted free agent to a three-year entry-level contract, but assigned him to continue his play in the WHL with the Saskatoon Blades. Playing with the Blades during the 2012–13 season, Makarov was awarded the Hap Emms Memorial Trophy as the most outstanding goaltender at the 2013 Memorial Cup. In 115 career WHL games with Saskatoon, Makarov went 66-38-7 with a .916 save percentage, a 2.80 goals against average (GAA), and nine shutouts.