Matildas stars Mary Fowler and Aivi Luik ruled out of Nigeria clash ...

Still reeling from Sam Kerr’s injury-enforced absence, two more Matildas stars have been ruled out of Thursday night’s FIFA Women’s World Cup clash with Nigeria after a double blow at training.

Starting forward Mary Fowler and veteran defender Aivi Luik suffered concussions in separate incidents on Tuesday, Football Australia said.

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“Fowler and Luik have both fully recovered and commenced FA’s graduated return to play protocol,” the FA said in a statement.

The news - announced moments before training began on Wednesday - will force coach Tony Gustavsson to make at least one change to the starting XI that will face Nigeria at Brisbane Stadium.

Fowler stepped into the considerable void left by Kerr for the opener against Ireland last Thursday and was again due to line up alongside Caitlin Foord in attack this week.

Mary Fowler filled in for the injured Kerr against Ireland. Credit: AAP

Fowler walked laps at training on Wednesday then started running later in the 15-minute window available to media.

The 20-year-old and Luik, 38, could both be available to face Canada in the Matildas’ final Group B clash on Monday, just six days after the concussion incidents.

But Fowler’s blow, with Kerr seemingly unlikely to be available before the knockout stage, has exposed a lack of forward depth in the Matildas squad after Gustavsson opted to carry Kyah Simon, who is still on the comeback trail from an ACL injury, into the tournament.

Emily van Egmond and Alex Chidiac are the leading options to replace Fowler in a reshuffled line-up, though Tameka Yallop has recovered from a corked thigh, while Clare Wheeler would be an outside-the-box choice.

Fowler ran laps at training on Wednesday, two days after her concussion. Credit: AAP

Tuesday’s troubled training session was closed to media but host broadcaster Optus Sport was on hand to interview Fowler afterwards.

They were instead told by the FA that Fowler had suffered a knock late in the session and required a precautionary assessment.

FA later allayed fears over Fowler’s condition, claiming she was “all good”.

Luik was an unused substitute against Ireland but has been in the mix for cameo appearances, having come off the bench in the friendly win over France two weeks ago.

The concussed defender did not join Fowler in walking and jogging at training on Wednesday, while Alanna Kennedy was on track with the main group after sitting out on Sunday and Monday for loading reasons.

Kerr, who shared photos of herself working out in the gym last week, walked laps for her most significant activity in public since the injury.

Matildas coach Tony Gustavsson will be forced to shuffle his line-up. Credit: Mark Metcalfe/FIFA via Getty Images

As the only Group B side to win their opening game, Australia can seal a spot in the knockout stages with victory over Nigeria.

If Canada (one point) and Ireland (zero points) draw in Perth on Wednesday night, the Matildas can secure top spot with a win on Thursday.

After drawing 0-0 with Canada first up, Nigeria may need to open up to chase three points - something that would have suited Fowler and could still pay off for Australia.

“It’s going to be another second-ball game and hitting them on transition. They obviously put a lot of numbers forward,” star midfielder Katrina Gorry said.

“So if we can try and hit them on transition, I think we’ll give them a tough time.”

- with Anna Harrington, AAP

Mel McLaughlin and broadcasting legend Bruce McAvaney are leading Seven’s coverage of the FIFA Women’s World Cup, with expert insight from Elise Kellond-Knight, Heather Garriock and more. Watch the Matildas and other key matches live and free on 7plus.

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