Socceroos boss Ange Postecoglou paid an emotional tribute to Tim Cahill, describing the midfielder as a "great Australian who transcends sport", ahead of his side's must-win Confederations Cup clash with Chile in Moscow.

Cahill will win his 100th cap for the green and gold if he takes the field at Spartak Stadium, the latest highlight in an impressive career that has seen him play top-flight domestic football in England, the United States, China and Australia.

The former Everton midfielder did not make his Socceroos debut until he was 24, following a nine-year battle for eligibility due to playing at youth level for Samoa, and Postecoglou believes his achievements rank up there with the greats in Australian sport.

He said: "It's not just football, to Australia as a nation, he's a great Australian, he transcends sport. To play 100 games for your country, to score at three World Cups... and he didn't start his international career until he was 24, not because of ability but because of other factors, so he could be sitting here with 120, 130 caps.

"And every one has been earned. If he plays tomorrow [Sunday] it's because he has earned it.

"He's just a great Australian and hopefully he'll be recognised for this, not just by the football community but from the country as a whole.

"I've no doubt that if it was any other sport in our country, he'd be held up as that, he's conquered the world.

"We've done it in tennis, in golf, you name it, the Olympics where we've had world champions and that's what this guy is.

"He's scored at three World Cups, if that's not world class then I don't know what is.

Cahill, 37, has no plans to retire from international football and played down the significance of his landmark moment, insisting all focus should be on beating Chile by the required two goals to progress to the semi-finals in Russia.

He said: "I love my country, I love playing football.

"I have played with so many players and great coaches and every single one has said never retire too early, don't give up this game as long as you can still play.

"This moment takes me back with the boss when we sat down in a hotel with Mark Bresciano, Mile Jedinak and a few of the other older players and you're nervous because you don't know what's next.

"But the boss said to me before the last World Cup, "why can't this be your best World Cup?" and funnily enough it was.

"And then we went to the Asian Cup and he said, "no it doesn't stop there, why can't this be your best Asian Cup?

"I get up in the morning because I am obsessed with the game, obsessed with giving back to my country but, more than anything, giving back to the players I play with.

"I am lucky to have a manager that believes in me. I had to stay on this journey because I believe in the project. And we will succeed. It might not happen in the next two weeks but it will happen and I am not going anywhere.

"I am always working to keep my body professional and my stats high and thank the boss and the staff for believing in me.

"My job is to stay professional, it's not about 100 caps, it's about beating Chile and trying to do good things for our country.

"After the game we can enjoy 100 caps, if selected. If not, we can do it after the next one. It's never been about 100 caps, it's about changing the game that we love in Australia."