Dockier comes from a real hockey family; not only his father and sister but even aunts and cousins have been playing field hockey.[2]
During his youth, he played for Royal Beerschot THC, where he played in the first team until 2014, when he left to play for Dutch club HC Den Bosch. After three seasons with Den Bosch, he went back to his former club.[3] He played there for one season before returning to the Netherlands to play for Den Bosch again.[4][5] In June 2020, he left Den Bosch and joined Pinoké for the 2020–21 season.[6] In his third season at Pinoké, he won the national title which was the first league title for Pinoké.[7]
He became European vice-champion with Belgium at the 2013 EuroHockey Championships on home ground in Boom and at the 2017 EuroHockey Championships in Amstelveen, Netherlands. He was a part of the Belgian squad which won the silver medal at the 2016 Summer Olympics. He was selected for the 2018 World Cup, which was his second World Cup.[8] On 25 May 2021, he was selected in the squad for the 2021 EuroHockey Championship.[9] During the start of the 2023–24 season, he was dropped from the national training squad for the 2024 Summer Olympics.[10]
