World Cup opener motivation enough for Matildas

Beating United States for the first time is no extra motivation for Australia in their Women's World Cup opener, according to Matildas coach Alen Stajcic.

The two nations have met 25 times and Australia have never come away victorious.

While eager for that to change when the teams meet in Canada on Tuesday morning (AEST), Stajcic said the World Cup was motivation enough.

"I don't think there's any extra motivation," he told a pre-match news conference.

"If playing in a World Cup isn't enough motivation, then you really shouldn't be here. I don't think anyone really looks at history books before you play a game.

"You just go out there and want to win that match and every match is an individual match in its own right.

"We want to beat America because we want three points, not to make history with whatever has happened in the past."

They are likely to be without co-captain Clare Polkinghorne, who is battling a hamstring injury.

Stajcic said a decision was yet to be made, but he expects the 26-year-old to miss

"She (Polkinghorne) is probably unlikely for tomorrow,” he said.

“She’ll have another fitness test tomorrow morning but I’d probably say she’d struggle to be fit for tomorrow’s game."