Olympic champions the USA roared home to spoil Sarah Walsh's Matildas farewell, but the Australian soccer stalwart scored a memorable goal in her final soccer international.

One of Australia's all-time greats, Walsh capped her 71-game career with a 32nd career goal and believes the young Matildas are on the way up despite succumbing 6-2 to the might of the Americans in Denver, Colorado on Wednesday.

Walsh remembers the days early in her eight-year international career when Australia were flat out getting a corner against the US.

But after the disappointment of missing out on the London Games, Australia have showed promising signs in the two matches against the world's best in California and Colorado.

Despite losing the two games, Australia led during both encounters and Walsh says she's leaving the Matildas in a good place.

"Most definitely. I was just saying to the girls earlier there was a time ... and it's bit of an exaggeration, but we would celebrate corners against the US," Walsh told AAP.

"I guess it's bitter sweet with the scoreline how it finished, but it's pretty fitting to be able to finish with a goal. Especially when we were one up on them as well."

Walsh appeared for the Matildas at the 2004 Olympic Games, the 2006 and 2010 AFC Women's Asian Cup's and the 2007 FIFA Women's World Cup.

Australia coach Tom Sermanni said Walsh had done herself proud.

"Apart from the result you can't go out any better than that," said Sermanni.

"She scored the goal, she played fantastic and she'll be a huge loss to the team on and off the field."

In the second and final match against the US, Walsh fired the Australians in front 2-1 late in the first half with a low shot past goalkeeper Hope Solo.

However Alex Morgan levelled for the home team a few minutes later and the floodgates opened as Abby Wambach broke the 2-2 deadlock with a deflection in the 53rd minute before Morgan completed her hat-trick with two more goals.

Three days earlier, the Australians led the first international 1-0 through Lisa DeVanna goal before going down 2-1 in Carson, California.

Sermanni said the American tour has been "unbelievably" valuable for his rookie team.

"I think in the first half we weathered a bit of a storm early on because the US came out fired up after the last game. We got ourselves in front and I'm really pleased with how we played in the first 45," he said.

"In the second 45 you saw the difference between a team that's at their peak and a team that's very mature and very battle hardened against our team in the very early stages of its preparations.

"But overall this has been an unbelievably valuable exercise for us."