Australian football great Robbie Slater says Sam Kerr must “play from the opening whistle” when the Matildas take on Canada in a last-ditch Women’s World Cup clash on Monday.

Australia, on three points, must beat Canada, which has four, at AAMI Park on Monday night to guarantee passage to the round of 16.

Otherwise, their only other option to avoid an embarrassing group stage exit is to draw and rely on Ireland, which is still pointless, to beat Nigeria (four points), likely by two or more goals.

Captain Kerr has missed both World Cup matches so far with a devastating calf injury. She has said she will return in some capacity on Monday, with an impact substitute role appearing likely.

But Slater said she should be named in the starting line-up.

“While it’s hard to imagine that Kerr’s injured calf is fully recovered after she, at the very least, strained it two weeks ago, if she says she is fit then there’s no use in delaying her comeback any further,” Slater wrote in a column for News Ltd on Monday.

“Starting her on the bench in Melbourne and bringing her on, a likely substitution scenario should the Matildas be in desperate need of a goal in the second half, would be another mistake from coach Tony Gustavsson.

“Instead, Kerr should play from the opening whistle.”

Slater’s comments came as Gustavsson said a call on Kerr’s match role would not be made until the last minute.

“I want to be clear that we knew she was going to miss the first two games and then be assessed going into this game, and that was going to go down to the wire,” Gustavsson told News Ltd on Monday.

“We’re going to have a meeting with the medical team and Sam, and discuss what the possibility is for her to play [against Canada].

“Then we’re going to do some tests [on Monday] to see what it looks like.

“There’s a lot on the table to discuss and we probably won’t know how exactly we’re going to use that until we come into the stadium [on Monday”.”

Another injured Matildas great, Elise Kellond-Knight, backed Kerr to play a substitute’s role.

“It’ll almost have more impact, her coming in off the bench,” she said.

“Putting her in at that 60-minute mark, or wherever it is, actually lifts the whole team, it gives everyone confidence.

“If she’s around the team warming up, that gives them confidence as well.

“But also being able to put a player like her into the field, mid-game gives the team this massive sense of energy, confidence and a really big push.”

Kellond-Knight has also tipped her teammates will triumph against Canada.

“We’re just better when we’re up against it. With that extra demand on the team we actually play better,” she said.

“The group will just get around each other like ‘the story is we are not going home, this is our home World Cup, we will not let this fall over before we get out of the group stage’.

“I’m confident they’ll make it happen. Because we have the ability – it’s just more of a mental thing.”

Three-time World Cup attendee Kellond-Knight is working for Channel Seven while sidelined with an achilles injury.

-with AAP