Johnston joined HGC in the Dutch Hoofdklasse in 2021 after the 2020 Summer Olympics after having played for the Vancouver Hawks.

He was part of the Canadian squad that competed at the 2015 Pan American Games and won a silver medal.

[7] In June 2021, Johnston was named to Canada's 2020 Summer Olympics team.

[8][9] He was the top goalscorer at the 2022 Men's Pan American Cup with ten goals as Canada won the bronze medal.

This biographical article relating to a Canadian field hockey figure is a stub.