After representing New South Wales (NSW) at a junior level Armstrong began his senior career playing for the Western Suburbs (1964–65) (1967–70) club. Originally a  Armstrong developed into a tough, uncompromising .
Following his junior representation of New South Wales (NSW), Armstrong commenced his senior career with the Western Suburbs club from 1964 to 1965 and again from 1967 to 1970. Initially an Armstrong, he eventually became a tough, uncompromising player.