Australia captain Sam Kerr said finally getting onto the pitch at her home Women's World Cup on Monday was a relief, but conceded that her teammates had probably not needed her contribution to reach the quarterfinals.

Kerr has spent much of Australia's first four matches recovering from a calf injury sustained on the eve of their opener but finally made her tournament bow with the Matildas already 2-0 up against Denmark in their last 16 clash.

The 75 784 fans crammed into the stadium built for the 2000 Olympics rose as one to greet the entry of the world class striker as a substitute in the 78th minute.

"Me coming on, personally, it was big relief after a big three weeks," she said.

"It was amazing. Obviously it's a big game for us. Bit nerve-racking. I'm not the best bench player in the world, I was nervous.

"The girls smashed it. They've done unbelievable this week. To put in that performance after a big game is amazing."

That big game was the 4-0 thrashing of Olympic champions Canada which secured Australia's passage into the knockout rounds as group winners as well as killing off any concerns that the Matildas might struggle without Kerr up front.

Again on Monday, forwards Caitlin Foord and Hayley Raso found the net with Mary Fowler, playing as a false nine, providing the key passes for both.

"I was going to play last game but the girls smashed it. They didn't need me," Kerr added.

"Today, there was the possibility that I wouldn't play if the girls smashed it. We thought it was best for me and the team, and the girls absolutely killed it. I'm so proud of them."

Australia coach Tony Gustavsson said the decision to bring on Kerr had not been straightforward and his heart had been in his mouth when she took a tumble in the box late in the game.

Looking forward to the quarterfinal against France or Morocco on Saturday, the Swede said his biggest problem now that Kerr is back might be who to leave out of his team.

"I think it's important if a team is going to be successful, you can't only rely on one player," he said.

"But I think Sam coming back now could be a good thing in the sense that we don't need to look to her to take over and have everything on her shoulders. It's a team effort and a team tournament. She's the icing on the cake.

"But that also means the players are challenging me now because I've got more than 11 players that deserve to start."