North Melbourne midfielder Jed Anderson is yet to have his second COVID-19 vaccination and has not returned from Darwin for the AFL pre-season.
The virus surge continues to hit the AFLW, with St Kilda coach Nick Dal Santo and Western Bulldogs captain Ellie Blackburn sidelined for next weekend's second round.
Now North have confirmed that Anderson had a poor reaction to his first jab and has not received the second.
Under league rules, AFL players in Victoria must be double vaccinated to take part in pre-season training.
"We will continue to work with Jed on next steps, but in the short term he will remain in Darwin, where he will complete his training program.
Our club fully supports the AFL's vaccination policy and in the interests of community health and safety, we urge everyone to receive their full course of vaccinations and booster shots."
Meanwhile, Dal Santo must sit out St Kilda's round-two AFLW game against Collingwood on Saturday under the league's health and safety protocols.
Player development manager Paddy Hill will coach them against the Magpies.
"As with everyone at the moment, we have to remain flexible and roll with the punches," Saints AFLW football boss Tessie McManus said.
"Nick will still be heavily involved in our program, albeit off-site for the next few days.
"I have no doubt Paddy will do an excellent job coaching the side this week."
Western Bulldogs captain Ellie Blackburn, their best player in the round-one loss to Melbourne, will also sit out their round-two game against Geelong on Saturday night according to the AFLW website.
North captain Emma Kearney is expected to return for their Sunday away clash with Adelaide.
Kearney had tested positive to COVID-19, but was available for last Saturday's win over Geelong.
She still sat out the game as a health precaution.