Queensland Health Minister Steven Miles says NSW has until Thursday night to find the source of three unlinked COVID-19 cases or the clock to reopen the border could be reset.
The state border has been closed since August 8 and Queensland has set NSW a target of recording 28 days of unlinked community transmission before it fully reopens.
NSW went for 12 days without a new case, but that's now at risk after three new cases emerged in western and southwestern Sydney after 8pm on Tuesday.
Dr Miles said NSW contact tracers had 48 hours to try to link the cases to existing clusters.
"I really hope they can," he told reporters late on Wednesday.
"If they can then that won't have any effect on our timeline so as far as we know for now, we are still on track for a review towards the end of the month and a potential reopening on the first of the month.
"If these cases aren't linked then that will need to be revised ... we would consider pushing that date back.
"If they can't be linked within two days then the link isn't sufficiently clear."
The deputy premier stopped short of saying the clock would be reset and said the "specifics" would need to be looked at by the chief health officer before a decision was made.
Queensland recorded no new cases of COVID-19 on Wednesday, with just seven active cases in the state.
Meanwhile, Dr Miles said the government has intervened in the case of a man with brain cancer who was denied a request to quarantine after Premier Annastacia Palaszczuk said she was not happy with his treatment.
Gary Ralph, 71, had surgery in Sydney last week and arrived back in Queensland with his wife Wendy Child on Tuesday, but he was ordered into hotel quarantine.
The operation has reportedly taken away Mr Ralph's ability to speak or even hold a pen and his NSW doctor has asked Queensland Health to allow him to quarantine at home.
The health department was allowing him to leave the hotel for chemotherapy treatment but he must travel by taxi or ride-share, in the back seat with the windows down, and must wear a mask.
Ms Palaszczuk says Mr Ralph's situation is "very distressing" and she's asked Mr Miles to look into his case.
"That's very distressing and can I say I'm not happy with the way Queensland Health has dealt with that at all," she said.
Dr Miles said Mr Ralph had been moved to a government medi-hotel along with his wife for quarantine, and is also being taken to medical appointments in an ambulance.
He said if that was insufficient then a room in a hospital will be made available for Mr Ralph to recuperate.
"We've had to be very consistent about this, but ultimately in a medi-hotel or hospital we can provide more and better health supports than we could in home quarantine," the deputy premier said.