Coach Andries Jonker has warned his Netherlands team to expect a South Africa side that gives their "heart and soul" when they meet in the Women's World Cup last 16 on Sunday.

The 2019 runners-up are especially wary after so many shocks at the tournament, including South Africa's 3-2 win over Italy that saw them into the knockouts for the first time.

"I think it's another fight at the World Cup between a so-called smaller country -- I think many people in women's football will consider South Africa smaller -- and a bigger country," Jonker said on the eve of the clash in Sydney.

"At this championship we see every night how the most famous countries fail against other countries who are also well trained, play with passion, defend well and play top football," he added.

Reflecting on 54th-ranked South Africa's victory over 16th-ranked Italy, Jonker said: "They play with heart and soul, for the people in the country. There's a big heart in the team, a fighting spirit.

"It's a dangerous opponent for us."

Coming into the tournament, the Netherlands were not thought to be quite the force they were when they reached the final four years ago before losing 2-0 to the United States.

But even missing injured star striker Vivianne Miedema, the Netherlands moved into the last 16 with relative ease, beating Portugal 1-0, drawing 1-1 with the US and then thrashing Vietnam 7-0.

The winner of Sunday's game will face Switzerland or Spain in the last eight.