A farmer in Bayles, Victoria, Harker played with Brunswick in the VFA for eight years, before making the decision to play for the Melbourne in the VFL, the highest level of Australian rules football competition at the time.Main & Holmesby (1992), p.173. He debuted for Melbourne in round 2 of the 1920 season against Essendon, at 32 years of age, making Harker the oldest player to ever debut for the Melbourne Football Club.
