2009-10: Sergey Tolchinsky skated for the CSKA 1995-born team and represented Moscow in the Russian tournament for 15-year-olds. He scored 31 goals with 17 assists and 8 penalty minutes in 23 regular season games. In five playoff games he scored 3 goals with 3 assists and was +2 with 12 penalty minutes. Tolchinsky scored 4 goals with 3 assists and was +5 with 2 penalty minutes in five games for Team Moscow.
2010-11: Tolchinsky represented Russia in three international U16 tournaments and played for CSKA's 1995-born team which reached the Russian championships. He scored 11 goals with 11 assists and 6 penalty minutes in 14 league games for CSKA. During the Moscow championship he scored 15 goals with 13 assists and 26 penalty minutes in 15 games. Tolchinksy scored 1 goal with 3 assists and was +3 with 2 penalty minutes in five games at the Russian championship.
2011-12: Tolchinsky made his debut in Russia's U22 MHL as a 16-year-old playing for Red Army Moscow and skated for Russia's U17 team in the 2012 World Hockey Challenge in Canada. He scored 19 goals with 15 assists and was +17 with 26 penalty minutes in 51 regular season games for Red Army. The Moscow club finished second in the Central Division. Red Army defeated Atlant in the West Conference Finals before falling to Omsk in the MHL Finals. Tolchinsky scored 2 goals with 2 assists and was -2 with 6 penalty minutes in 15 playoff games. He scored 3 goals with 14 penalty minutes in five games for Russia's gold medal squad at the WHC. Tolchinsky was selected by CSKA Moscow in the first round (28th overall) of the 2012 KHL Draft and was chosen by Sault Ste. Marie (OHL) in the first round (12th overall) in the 2012 CHL Import Draft.
2012-13: Tolchinsky skated for Russia's U18 team in the 2012 Ivan Hlinka Memorial Tournament before heading to Canada for his first OHL season with the Greyhounds. He finished the year playing in Sochi with Russia's U18 team at the 2013 World Junior Championship. Tolchinsky scored 26 goals with 25 assists and was +8 with 12 penalty minutes in 62 regular season games for Sault Ste. Marie. The Greyhounds finished second in the West Division and face Owen Sound in a first round playoff series. Tolchinsky scored 2 goals with 2 assists and was -7 with 4 penalty minutes in six playoff games. He scored 3 goals with 1 assist in four games for Russia at the Ivan Hlinka tournament and scored 3 goals with 1 assist, finishing +5 with 2 penalty minutes in seven games at the WJC. Tolchinsky was ranked 118th amongst North American skaters in Central Scouting's final rankings but was not selected in the 2013 NHL Draft.
2013-14: Tolchinsky was invited to the Carolina Hurricanes training camp and signed a three-year entry-level contract with Carolina in August before returning to Sault Ste. Marie for his second season. He made his pro debut with the AHL's Charlotte Checkers in April after the Greyhounds were eliminated from the OHL playoffs. Tolchinsky was -1 with no points nor penalties in his only AHL game. He was the Greyhounds' leading scorer with 31 goals and 60 assists and was -9 with 22 penalty minutes in 66 games. Sault Ste. Marie finished first in the West Division and reached the second round in the playoffs. Tolchinsky scored 2 goals with 4 assists and was -1 with 4 penalty minutes in nine playoff games.
Tolchinsky signed an entry-level contract with the Carolina Hurricanes in August, 2013.