Australia defender Jade Warrender has ruptured her anterior cruciate ligament and will miss this summer's Olympics.
The 19-year-old sustained the injury, the second of her career, during training in Perth this week and will undergo reconstructive surgery next week.
She is expected to be sidelined for at least nine months.
"We have a squad of 27 and that is justified when something like this happens," said Hockeyroos coach Adam Commens.
"While devastating for Warrender, this now opens up a back-line position and Jacklyn McRae, Jayde Taylor and Kate Jenner are likely to press for selection in defence."
Warrender is the second Australian player to suffer a cruciate ligament injury inside a week, as men's defender Graeme Begbie was injured in a practice match ahead of last week's test event in London.
