Captain Sam Kerr has declared herself available to play in the Matildas’ do-or-die Women’s World Cup match against Canada in a massive boost to Australia’s precariously placed campaign.

But just how many minutes the superstar striker will or can manage remains a mystery.

Kerr, Australia’s all-time leading scorer with 63 goals in 121 games, injured her left calf the day before the Matildas’ opening game against Ireland and hasn’t played since.

The 29-year-old put the boots on for the first time since her injury at Saturday’s closed training and subsequently confirmed her availability.

Australia’s campaign is on a knife’s edge after Thursday’s 3-2 loss to Nigeria and the Matildas realistically must beat Canada to guarantee progression to the round of 16, without relying on Ireland to beat the Super Falcons.

Kerr wouldn’t be drawn on exactly how many minutes she could handle but when asked to clarify if she would be fit to play if selected, said: “Yes”.

“I feel good. The plan has always been the same, miss the first two games and then reassess,” she said.

“I’m feeling good. I was out on the pitch today. As good as I can be.

“I would love to tell you guys everything but ... that’s a massive thing that the opposition wants to know.

“It’s going to be down to the wire - I’m definitely going to be available but how we decide to use that is not to be given to the opposition.”

When asked how Kerr looked on the track, defender Ellie Carpenter said with a smile: “Like Sam”.

“I’ve done everything I can and no matter what happens, I know that I’ve given everything, not just in the last 10 days, in the last four years, I’ve given everything to be here,” Kerr said.

Kerr joked she’d been stunned by the injury as she had “the biggest calves in the world” but had quickly moved on.

“I’ve never had an injury like this in my career. I mean, touch wood this is the last,” she said.

“Normally when I’ve been injured it’s been really a big one where I’ve been out for months on end, so it’s an easy pill to swallow, but with these ones it’s a bit more annoying.

“It was obviously disappointing and then I had to kind of suck it up. I’m part of a team. I’m not a part of an individual sport.

“It’s not about me, and that’s what I’ve done over the last however many days it’s been - I’ve had to put the team first.”

Fellow striker Mary Fowler, who missed the Nigeria loss with concussion, should also return.

The Matildas (three points, goal difference 0) sit third in Group B behind Nigeria (four points, +1) and Canada (four points, +1).