Victorian Chief Health Officer Brett Sutton said there was nothing unusual about the case.

"It's a positive test. It's being treated as a confirmed positive. There are lots of people who test positive one day, they're at the very tail-end of their infection and then they test negative the following day. If you get two negative tests 24 hours apart, you as a case are clear. But your close contacts, [from] when you are potentially infectious, they have to go through their 14-day quarantine period. That will apply to Conor McKenna's contacts," Sutton said.

"[For anyone like that], their virus is at low levels now, they are recovering, and two negative tests give us the confidence that someone isn't infectious. So I think that's the case here in all likelihood."

Speaking hours after Sutton addressed the media, Worsfold said that while he retained faith in the authorities and the process, McKenna's most recent negative test had planted seeds of doubt in his mind.

"There's some doubt in my mind. I don't know if there's doubt in other people's minds but again, we're waiting to find out exactly what it means," Worsfold said.

"There's some pretty smart people out there that will assess what Conor's testing results are saying, but he's had some positive tests, with some negatives around that. From my own personal point of view, if you said 'has he definitely got it?' I couldn't answer that."

But Worsfold backed the system that has seen AFL club players and staff routinely tested to prevent against a coronavirus outbreak.

"It appears to be working. We get temperature checked every time we come into the club, and we get our actual swab testing done twice a week. We'll stick with that and we'll back the results in until someone tells us otherwise," he said.

With their match against Melbourne last weekend postponed, Worsfold said the Bombers were keen to take on Carlton on Saturday night, but that they would do so with somewhat heavy hearts given the respective fates of McKenna and Stewart.

"It's mixed [emotions]. Because we are really feeling for James Stewart and Conor. Conor potentially has the COVID virus and James is in quarantine for two weeks, and that is very tough to deal with, a young man who had worked extremely hard to get himself back on the brink of selection. So we feel for them, but the players know we've got a game to play and they'll be excited about getting out there and representing the club really well."

Worsfold added that Orazio Fantasia (quad) would need to prove his fitness to take on the Blues. Joe Daniher (thigh) won't play in a scratch match this weekend and Worsfold wouldn't say whether the forward would play in the coming weeks.