Dr Ronan Glynn has said they will need to monitor Thursday's cases jump before thinking about a move to phase four next week.
At the moment, August 10 is the date set for the move to phase four which will see all pubs allowed to open.
This was originally supposed to happen on July 20 but was pushed back due to another sudden spike in cases.
The National Public Health Emergency Team will meet next week to discuss the planned move but much depends on how the next few days go.
Speaking on Morning Ireland, acting Chief Medical Officer Dr Glynn said the next 24 hours will be monitored closely.
The top doctor said: "We're due to make a decision on that phase next week but for now we have to concentrate on the next 24 hours, 48 hours.
"We need to see whether this 85 cases leads to a further jump or a blip.
"Hopefully it's a blip and we will give further consideration to the phase next week but it's quite a distance off at this stage."
The doctor said a number of days ago that pubs remain a "high risk" environment and there is no guarantee they will open on August 10.
Dr Glynn added that the main cause of concern amongst health experts is people forgetting to maintain social distancing.
He said: "This virus can only transmit when people come into contact with one another, [but] it's completely understandable that as things have improved, people have dropped their guard in relation to that."
A further 85 cases were confirmed on Thursday with just one more death.
Should the cases continue to rise in the coming days, it is thought to be less likely any move to phase four will occur.
