Victorians who test positive now must isolate for seven days, down from 10, following the National Cabinet moves.
PCR tests are now only available for people who have tested positive on a rapid antigen test, and new close contact rules mean only household contacts who have been near a positive case for more than four hours need to get tested and isolate.
"The only people who should present at a state site for PCR testing are people with symptoms or people who have tested positive on a rapid antigen test," Mr Foley said.
Mr Foley said he expected more stock of RATs to become available in coming days.
Shepparton recorded 18 new cases of coronavirus on Friday for a total of 102 active cases, while the figure meant the city recorded 1720 cases of the virus for 2021.
Victoria as a whole recorded 5919 new cases and seven deaths, while hospitalisation numbers increased to 428.
NSW recorded more than 21,000 new cases and a significant jump in hospitalisation numbers, while Queensland and South Australia passed 3000 and 2000 new cases respectively.
Mr Foley said case numbers would continue to go up in Victoria, with a third of all cases now the highly-infectious, but less severe Omicron variant.
“In the coming months, on all the projections we've seen, we will see substantial increases in cases," he said.
The GV Health testing clinic at Shepparton Showgrounds closed on Friday at 12.45pm due to the heat, and testing sites across the state may be impacted by the heatwave.