2010-11: Alexander Protapovich played for Ak Bars Kazan's 1996-born team in the Povolzhie region of Russia and skated for Povolzhie's U15 team in the national tournament. He scored 2 goals with 4 assists and was +4 with 25 penalty minutes in five games for Ak Bars Kazan at the Russian U16 national tournament and scored 2 goals with 5 assists and 2 penalty minutes in six games in the 1996-born tournament. Protapovich scored 4 goals and was -1 with 2 penalty minutes in five games for Povolzhie.
2011-12: Protapovich skated for Ak Bars Kazan as the club reached Russia's U17 championships and played for Russia's U16 team in a pair of tournaments. Ak Bars again captured the Povolzhie region championship and in six games at the Russian championships Protapovich scored 6 goals with 5 assists and was +9 with 4 penalty minutes. He scored 3 goals with 5 assists and was +5 for Russia at the 2012 Youth Winter Olympic Games and was +1 with no points and 2 penalty minutes in three games at the 2012 Four Nations Tournament.
2012-13: Protapovich played junior hockey for Irbis Kazan in the MHL's B Division and played for Ak Bars Kazan in the U17 Russian championship. He played for Russia's U17 team in five international tournaments. Protapovich scored 9 goals with 6 assists and was +15 with 36 penalty minutes in 30 regular season games and was -4 with no points and 12 penalty minutes in five playoff games for Irbis. He scored 4 goals with 17 assists and was +2 with 8 penalty minutes in 15 games for Russia's U17 team. In three games at the Russian U17 champions for Ak Bars he scored 1 goal with 5 assists and was +4 with 2 penalty minutes. Protapovich was selected by Ak Bars Kazan in the first round (sixth overall) of the 2013 KHL Draft and was taken by the OHL's Niagara Ice Dogs in the second round (80th overall) of the 2013 CHL Import Draft.
2013-14: Protapovich made the move to North America; skating in 46 regular season games for Niagara in his first OHL season. He scored 4 goals with 9 assists and was -14 with 16 penalty minutes — missing time with an abdominal injury. The IceDogs finished fourth in the Central Division. Protapovich was ranked 166th amongst North American skaters in Central Scouting's mid-term rankings prior to the 2014 NHL Draft.