The state recorded 11 new cases of COVID-19 on Thursday, six of which are connected to known outbreaks while five are under investigation.

Melbourne needs a 14-day average of five cases to reach the 'third step' of the state's roadmap out of restrictions, which involves retail and some hospitality venues reopening and the five-kilometre limit being scrapped.

The city must also record no more than five mystery cases within the same period.

It was initially predicted Melbourne would reach this stage by October 26, but Mr Andrews brought the date forward to October 19.

Melbourne's 14-day average stands at 9.7 cases, while 14 mystery cases have been recorded between September 22 and October 5.

Regional Victoria's 14-day average, meanwhile, has slightly increased to 0.4, from 0.3 on Wednesday. Its mystery cases remain at zero for the two weeks.

Victoria's Deputy Chief Health Officer Allen Cheng said it would be a "day-by-day assessment of the situation" as to when further restrictions are lifted.

"Every unknown source case represents at least one person who gave it to them, so we still are concerned about that," Professor Cheng told reporters on Thursday.

"That's I think the figure that concerns me most at this stage.

"We still have a little way to go, so we just need to keep an eye on those and continue to investigate those to see where they might have got it from."

The premier said it was "highly unlikely that nothing will change" come October 19.

"There will be some changes, the exact nature of those changes, we will need to look at," Mr Andrews said.

"We will do whatever's safe.

"But what people won't welcome, either from an intellectual point of view or from an emotional point of view really, are steps being taken that are not safe. That just runs the risk of setting us all back."

Authorities have been working to contain an outbreak linked to the Butcher Club at Chadstone Shopping Centre, which has infected 31 people and spread to Frankston in the southeast and Kilmore in the north.

The Kilmore cluster began when a person infected with COVID-19 linked to the Chadstone outbreak dined at the town's Oddfellows Cafe, in a breach of restrictions on September 30.

Hundreds of people who visited the cafe between September 30 and October 3 are self-isolating after a staff member contracted the virus.

The manager of the Chadstone butcher shop, meanwhile, was rushed to hospital on Tuesday after his condition deteriorated, according to The Age.

Some 15,298 tests were conducted across Victoria on Wednesday, including 294 in Kilmore. It follows 200 tests of Kilmore residents on Tuesday.

The premier urged any Victorian with symptoms - no matter how mild - to be tested.

"It's not the detection of a positive case that's the problem - that's exactly what we need," Mr Andrews said.

"It's about the spread of this virus without us knowing - that's what can set us back."

There is also a new case in the Mildura local government area, but Mr Andrews said it was likely a false positive.

Victoria recorded no deaths Thursday, with the state's toll from the virus remaining at 809 and the national figure at 897.

There are 17 Victorians battling the virus in hospital, including one person in intensive care.

For the first time since June 9, Victoria recorded fewer coronavirus cases than NSW, which had 12 infections including four returned travellers in hotel quarantine.

Australian Associated Press