Presumably Varnhagen loves being a nurse partly because it gives her job satisfaction to care for sick people in the intensive care units she works. The obvious inherent conflict in that statement is that one might wager the vast majority of hospital patients may not consent to being treated by an unvaccinated nurse. Such a situation arguably represents a form of coercion, which is why vaccination has been mandated for South Australia’s healthcare workers and why Varnhagen was one of almost 400 forced to take leave after refusing the jab, according to figures released by SA Health on Tuesday.

She also described the Covid vaccine as a “medical experiment”. On this, it should be noted the “experiment” phase of Australia’s approved Covid vaccines has long since passed. The human clinical trials have been done, and the Therapeutic Goods Administration stipulates a high threshold for approval. The real “experiment”, in this context, likely has more to do with her sporting endeavours – and those of her colleagues in this sphere who are also hesitant to take the Covid vaccine.

Australian sport is embarking on a clinical trial of its own, one of contractual obligations and interstate logistics. As borders begin to reopen, leagues and clubs are navigating a shift away from biosecure bubbles and towards freer travel but with strict regulations about who is allowed to travel where, on what airlines, and to which stadiums.

The AFL has already announced all AFL and AFLW players will need to be fully vaccinated by mid-February or be barred from playing and training. The NRL has not followed suit, but admitted the public health orders of state governments or airlines may force their hand. In Victoria, all professional sportspeople entering a stadium must be vaccinated, which would rule out the handful of players reportedly unwilling to get jabbed. Other state rules could yet mean they are unable to play a significant portion of the season.

Paul Gallen, hardly the oracle on weighty subject matter, made this salient point. “If a player doesn’t feel comfortable getting the vaccine then I don’t think they should be made to have it,” the former Cronulla and New South Wales captain said last month. “But if they’re not made to have it and don’t want to have it, they have to face the consequences that come with that.”

The players’ union is working with the NRL to develop a policy for handling unvaccinated players from 1 November, when those off-contract will be able to negotiate with rival clubs, but will still be subject to government restrictions due to their vaccination status. Until statewide vaccine mandates were implemented, the Rugby League Players Association expected NRL clubs would employ unvaccinated players.

It is an unenviable quagmire for clubs in any code. Already two NBL players have been released from their contracts – New Zealand Breakers guard Tai Webster and Illawarra Hawks import Travis Trice. Before long the A-Leagues and netball seasons will start. The Australian Open is already the subject of much controversy and conjecture.

Crows coach Matthew Clarke said on Wednesday he hoped Varnhagen would make the decision to be vaccinated before 19 November, when she is required to have had her first jab to be eligible to play.

“She’s continued to engage in the education from the medical team, from the AFL’s medical team and we see that as the opportunity, but ultimately it’s an individual choice,” Clarke told SEN SA. “She’s been training and doing all the work and been training really well. It’s obviously been a challenging period for her, and for all organisations having to confront this new situation.”

If Varnhagen refuses to comply with the AFL’s vaccination policy, the Crows will be able to replace her on their list before the sixth season of the competition begins on 6 January. Clarke confirmed every other AFLW player at the Crows will soon have received both vaccine doses.

“The club’s [view] is pretty clear,” he said. “We’re really promoting vaccination and we think it’s really important for the community and our industry. My perspective is that all of the medical advice and the health experts inform me that this is a safe and a really effective mechanism to diminish the impact [of Covid-19].”

At the protest, Varnhagen wore a white singlet emblazoned with the words “freedom to choose”. In terms of her career as both a nurse and AFLW player, her choice carries clear ramifications. For sporting bodies, the outcomes of their choices are less conspicuous.