Another American, Brett Brown, quit the job last October in the wake of the postponement of the Games for a year and his sacking by the Philadelphia 76ers.
Goorjian, the most successful coach in the history of Australia's National Basketball League, also led the Boomers at the 2004 Athens Olympics, where they finished ninth, and the Beijing Games four years later, when they were seventh.
His team for the Beijing tournament included NBA players Andrew Bogut, Patty Mills and Joe Ingles, who are all expected to feature in Tokyo as Australia seek their first medal in their 15th Olympic campaign.
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"Being reunited with some of the guys I previously coached at the Beijing Olympics is an exciting prospect," said the 67-year-old Californian.
"Australia is very fortunate to have such a talented group of athletes at this time. There is certainly a feeling of unfinished business, so there is a strong commitment from these players to participating in the Tokyo Olympics."
International Olympic Committee President Thomas Bach said on Wednesday that the NBA had agreed to a shortened season to allow players from the league to compete in Tokyo.
(Reporting by Nick Mulvenney, editing by ...)
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