"I've made it clear to the group that it'll be tough to make the squad for Rio if they haven't been selected for Darwin," he said.
"However, I have had a commitment from the non-travelling players that they will continue to work hard back in Sydney and maintain the high standards that this programme has set.
"As we have found to our detriment this past week, injuries can happen at any time so we need the entire group to be ready to step into the breach at short notice."
Apart from 15-test Cummins, a number of other capped Wallabies have tried out for Rio but have suffered injuries or failed to adapt to the format.
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Fiji-born winger Henry Speight was in the frame despite fracturing a bone above his eye in May but was ruled out by a serious knee injury last week after a mishap during a practice match.
Wallabies flyhalf Quade Cooper played world series events in Las Vegas and Vancouver earlier in the year but was dumped from the squad in May.
Australia are among 12 nations to have qualified for the men's sevens tournament at the Aug. 5-21 Rio Games.
(Reporting by Ian Ransom; Editing by Peter Rutherford)
