 He made his debut on March 2 in Montreal's season opener against the San Jose Earthquakes, as a substitute for Ignacio Piatti in the 85th minute.Brault-Guillard transferred to Montreal permanently on January 25, 2020.Brault-Guillard was named to the Canadian U-23 provisional roster for the 2020 CONCACAF Men's Olympic Qualifying Championship on February 26, 2020.