While the number of active regional COVID-19 cases has declined overall, this week there was 30,000 - or 17 per cent - fewer tests being conducted and processed statewide compared with last week.
"It seems logical that there would be less testing - but not this much less," Mr Andrews said.
"I don't want a situation where we see numbers continue to fall but at the same time the total number of tests falling also because that will mean we don't have confidence that we have an accurate picture of how much virus is in the community.
"We don't want that to be an inhibitor in any way of moving to a new phase and a new set of rules.
"We have to have that confidence that we are getting a complete, or as close to a complete picture, as we possibly can."
Mr Andrews said his "principal ask" was for anyone who had any symptoms, no matter how mild, to go to a COVID-19 testing location.
"We will get your results back to you as quickly as possible," he said.
"The lab teams are working very, very hard."
Goulburn Valley Health chief executive Matt Sharp said he was aware some people were waiting up to three days with symptoms before getting a COVID-19 test, and urged community members with symptoms to act faster.
Victoria recorded 222 new COVID-19 cases, and 17 deaths today.
Anyone who is unwell with any symptoms of COVID-19, no matter how mild - such as fever, chills, cough, sore throat, runny nose, loss of sense of smell - should get tested immediately and stay at home.
GV Health's Acute Respiratory Clinic at Graham St, Shepparton is open seven days a week from 8 am to 5.30 pm and does not require an appointment.
For more information, phone the coronavirus hotline on 1800 675 398 or visit www.dhhs.vic.gov.au/coronavirus
