Shaun McKernan has revealed he missed Essendon's round one win over Fremantle with pneumonia, after fearing he may have contracted COVID-19.

The Bombers key forward missed the clash at an empty Marvel Stadium with illness, having discovered that he had the viral infection.

With community transmission levels of coronavirus peaking around round one before the government's lockdown measures were in place, the 29-year-old had to undertake two COVID-19 tests.

He said he had thought he might have been infected with the COVID-19 pandemic.

"It was a bit worrying at the start because they weren't sure exactly what I had and then I got tested twice at that stage so it was a little bit scary," he said on Tuesday.

"I thought I might've had it, but they ended up figuring out it was pneumonia.

"It was pretty scary at that point because that was the height of it and people were running around a bit scared about it all but the doctors handled it pretty well."

With the AFL season suspended after round one, McKernan spent the first block of time away from the club recovering from the illness and slowly getting back into training.

"It was a bit of a shock, I didn't know how I'd gotten it or where I'd gotten it from. That was the question I kept asking the docs and they said it was a bug you could pick up anywhere," he said.

"It did knock me around for a bit. It probably took me a good one or two weeks after round one to get back into full running and my weights stuff again.

"But the doctors were fantastic with it all and got me back to full health."

McKernan will enter the restart of the season in strong shape, ready to head Essendon's forward line against the Swans at the SCG in round two.

He will be the Bombers' marking target close to goal with spearhead Joe Daniher (groin) out indefinitely, while James Stewart could also return to the senior side to partner McKernan in attack after recovering from his own groin issues.

"Joe's been in and out for the last couple of years and at times I've had to take on that role," he said.

"It's something that I welcome and something I get excited by. I like performing for my teammates and I know it helps us win games of footy so to me it's just business as usual."