Bradtke started his NBL career with the Adelaide 36ers in 1988, though by that time the team was being coached by Gary Fox. That same year saw the now 6'10" (208 cm) Bradtke was a member of the Australian Boomers team at the 1988 Summer Olympics in Seoul, South Korea, helping the team to an Olympic best ever finish of fourth place with a 4–4 record, losing the bronze medal game to the United States team which included future NBA players Dan Majerle and David Robinson. At the time, 18-year-old Bradtke was the youngest player ever having represented Australia in Basketball at the Summer Olympics (he would turn 19 during the preliminary rounds).