Don't attend sport if you're sick - that's the "number one thing players can do to protect their teammates and themselves" from COVID-19.
So says University of Newcastle Professor Brett Mitchell ahead of the return of community sport this weekend.
Professor Mitchell, an infection-control expert, said players and spectators should not attend if they're "unwell in any shape or form".
He added that it was "very important" for players to wash their hands before and after games.
And social distancing should be maintained as much as possible, including gatherings around the coach before games in team talks and huddles.
Celebrations should be "kept to a minimum to avoid contact" and shared containers of fruit at half-time should be kept off the menu.
Professor Mitchell said the risk of contracting COVID-19 in the Hunter was presently low.
"But there are still possible cases out there. We've seen that in Victoria. We don't want to be Victoria," he said.
He said people should get into the habit of following COVID guidelines at sport.
"COVID-19 is going to be here for a while. It only takes one person to turn up sick. If people aren't doing the right thing, we can get a cluster."
One of the important things about COVID-19 was "the frequency and amount of time you're in close contact with others".
"The longer you're in contact with someone, the greater the risk of transmission."
As a general rule, 15 minutes in close contact with someone is considered to increase the risk.
A study of 288 English Premier League matches this season found that 98 per cent of on-pitch interactions between players lasted less than five minutes in total.
Professor Mitchell said outdoor sports "have the benefit of being able to socially and physically distance a bit more and have natural ventilation".
"For indoor sports, minimising the time that you're indoors with other people is important."
He recommended cleaning shared equipment before and after each game, "particularly if it's shared over the course of the day by multiple teams".
"It doesn't need to be disinfected necessarily, just a simple clean with a detergent wipe or soap and water. That will help minimise the risk of spread."
Different sports will have different restrictions. But as a general principle, spectators should ask themselves whether it's "absolutely necessary" to be at a game.
"If you have a child, could just one parent go rather than two?"
Canteens and mobile coffee shops will have COVID restrictions in place, including social distancing.