Herey began fencing in the senior category in the 2009–10 season, earning a bronze medal in the 2010 Buenos Aires World Cup. He joined the Ukraine national team in the 2010–11 season and took part in the European Championships in Sheffield. Ukraine was defeated by France in the semi-finals, then by Russia, and finished fourth. Herey also participated in the 2011 World Championships in Catania. He defeated Switzerland's Benjamin Steffen in the first round, then ceded to Italy's Paolo Pizzo, who would eventually win the competition.