Sam Kerr at risk of missing entire Women's World Cup group stage

Australia staff will continue to asses superstar striker Sam Kerr in the hope that she will be fit enough to feature before the end of the Women's World Cup group stage.

As Australia's captain and best player, Kerr was set to be the face of this World Cup on home soil. Instead, a calf injury kept secret until the day of the team's opening game has ruled her out - there were audible gasps in the press room at Stadium Australia when news filtered through.

Kerr missed the narrow win over Republic of Ireland and will not play against Nigeria on Thursday. She could return to face Canada but there are no guarantees and coach Tony Gustavsson has stressed that no decisions on that front will be made until as late as possible next week.

"Most likely we won't be able to give an answer until the day before the [Canada] game. We want to wait until the last minute to see where she's at in terms of availability," Gustavsson said of Kerr's status ahead of his team's game against Nigeria.

"We have been as open as we can be to say it is a calf injury that is going to be reassessed after the Nigeria game. Me personally, I don''t know more than that as of now - I am just focusing on the players I have available and I know that's how Sam wants it as well."

Kerr isn't the only Australian forward ruled out of Thursday's crucial second game. Mary Fowler suffered a mild concussion in training, while Kyah Simon is also nursing an injury problem. It leaves just Caitlin Foord as the only recognised striker available for Nigeria.

"We have a lot of attacking options still in the roster," Gustavsson said.

"But this team have also showed that we're very adaptable. So we might have a different profile of a player or different formation but we're still going to have the same identity."