2007-08: Petr Zamorsky played for the HC Zlin U18 team in his hometown and skated for the Czech Republic U18 team. In 43 regular season games he scored 3 goals with 26 assists and was +24 with 38 penalty minutes. Zamorsky had 2 assists and was +6 with 4 penalty minutes in seven playoff games. In 11 games for the Czech U16 team he scored 1 goal with 1 assist and 4 penalty minutes.
2008-09: Zamorsky skated in 39 games in his second season with the Zlin U18 team. He scored 6 goals with 15 assists and was +17 with 150 penalty minutes. Zamorsky played four games for the Czech U17 team and had 2 assists with 6 penalty minutes.
2009-10: Zamorsky played for the Zlin U20 team as a 17-year-old — playing 28 regular season games and 11 playoff contests — and represented the Czech Republic at the 2010 U18 World Junior Championship. He scored 4 goals with 7 assists and was +12 with 18 assists during the regular season and had 1 goal with 1 assist and was minus-1 with 10 penalty minutes during the playoffs as Zlin won the U20 league championship. Zamorsky played nine games with the HC Zlin U18 team and was +7 with 1 goal, 8 assists and 26 penalty minutes. In six games for the Czech Republica at the U18 WJC he scored 1 goal with 1 assist and had an even plus/minus with 2 penalty minutes. Zamorsky was ranked 58th amongst international skaters in the CSS final rankings but was not selected in the 2010 NHL Draft.
2010-11: Zamorsky returned to the HC Zlin U20 team for a second season and played with the Czech Republic U20 team — though he did not skate in the 2011 World Junior Championship. He scored 6 goals with 18 assists and was +11 with 79 penalty minutes in 46 regular season games. HC Zlin finished fourth and lost to eventual champion Oril Znojmo in a quarterfinal series. Zamorsky had 2 assists and was an even plus/minus with 2 penalty minutes in three playoff games. In eight games for the Czech U20 team he scored 1 goal with 4 assists.
2011-12: Zamorsky skated for the HC Zlin men's team in the Czech Extraliga and played for the Czech Republic U20 team in the 2012 World Junior Championship. He scored 1 goal with 4 assists and was -11 with 34 penalty minutes in 37 regular season games. Zlin finished seventh in the regular season and defeated Trinec Ocelari in a preliminary round series before falling to Plzen in a seven-game quarterfinal series. Zamorsky played in 12 playoff games and had an even plus/minus with no points and 6 penalty minutes. In five games for the Czech Republic at the 2012 WJC he had 2 assists and was +2 with 6 penalty minutes.
2012-13: Zamorsky spent his second Extraliga season with HC Zlin and made his initial appearance with the Czech Republic national team — skating in three games during the Euro Hockey Trophy series against Russia, Finland and Sweden. He scored 8 goals with 5 assists and was +2 with 30 penalty minutes in 37 regular season games. HC Zlin finished second in the regular season and reached the finals; falling to third-place Plzen for the second straight season. Zamorsky had 4 assists and was +3 with 34 penalty minutes in 16 playoff games. In three games with the Czech national team he was minus-1 with no points nor penalties.
2013-14: Zamorsky was the second-leading scorer amongst HC Zlin defensemen in his third season and was second on the team in penalty minutes. HC Zlin captured its first Extraliga championship since 2003-04. Za,prslu also skated for the Czech national team in three of the four tournaments during the Euro Hockey Trophy series and at the 2014 IIHF World Championship in Belarus. He was named the top defenseman in the Czech Extraliga. In 44 regular season games he scored 7 goals with 11 penalty minutes and was +18 with 80 penalty minutes (four minutes fewer than veteran forward Pavel Kubis). After finishing fourth in the regular season HC Zlin rolled through the playoffs; defeating sixth-place HC Kometa Brno in the finals. Zamorsky scored 4 goals with 5 assists and was +8 with 24 penalty minutes in 14 playoff games. He had 1 assist and was +5 with 4 penalty minutes in nine games during the Euro Hockey Trophy series and in ten games at the World Championship he had 3 assists and 12 penalty minutes; finishing with an even plus/minus. Zamorsky signed a two-year entry-level contract with the New York Rangers on June 10th 2014.