Mr Andrews confirmed his diagnosis on Monday morning, forcing him and his family into isolation for seven days.

The premier decided to take a rapid antigen test after waking up with symptoms including a sore throat and mild temperature.

"Cath and the kids are negative, but as close contacts will isolate with me for seven days. My symptoms are mild and we're well-stocked on Panadol (sic)," Mr Andrews tweeted.

The positive result means he will not be among an expected crowd of 50,000 at the Melbourne Cricket Ground on Wednesday evening to officially farewell Warne, who died of a suspected heart attack on the Thai resort island of Koh Samui this month.

His deputy James Merlino will serve as acting premier until April 4, the day before state parliament is due to sit.

While the premier rests and recovers, Opposition Leader Matthew Guy wished him and his family well.

"We may disagree politically but I certainly don't wish him badly in any way in relation to his health. I hope comes through OK," he told reporters.

Mr Andrews had attended the official opening of the Broadway musical Hamilton at Her Majesty's Theatre in Melbourne on Thursday night with wife Catherine.

The pair were photographed wearing masks despite them no longer being mandatory in theatres and most other settings.

Victoria recorded 8739 new COVID-19 cases and no new deaths on Monday - the fourth consecutive day of new infections below 10,000.

The number of COVID-19 patients in Victorian hospitals has fallen to 252, after rising from fewer than 200 a fortnight ago.

VICTORIA'S LATEST COVID-19 FIGURES:

* Total deaths: 2727

* Active cases: 56,997

* Intensive care cases: 21

* Ventilated cases: six

* Positive PCR tests: 2226

* Positive rapid tests: 6513

* Victorians 18 and over with three vaccine doses: 65.2 per cent.

Australian Associated Press