The AFL has declined Hannah Mouncey permission to play in the AFLW.
Mouncey was set to enter the draft, but her bid to do so was knocked back by the AFL on Tuesday afternoon.
Fairfax Media reported the decision was based on the Victorian Equal Opportunity Act, which allows for discrimination based on sex or gender in situations where strength or physique are relevant.
Mouncey, who stands 190cm and weighs 100kg, played eight games for Ainslie in the Canberra's women's competition this year, kicking 17 goals.
She is able to go through a similar application process for the 2019 draft.
She is also able to register to play in other competitions over the next year.