A first win over Japan in 16 years in Perth on Thursday would put Australia well on their way to the finals in North America in 2026, but will not get them over the line if Saudi Arabia beat Bahrain in a later match.

The Socceroos have a three-point edge and a healthy goal difference advantage over the Saudis, their main rivals for second place in Group C and their opponents in their final qualifier in Jeddah next Tuesday.

The expansion of the World Cup means Australia still have room for error but Degenek, a veteran of the 2018 and 2022 World Cup campaigns that were secured by playoff wins over Honduras and Peru, is loathe to take any chances.

"It's never easy when you go to those knockout games (and) it's a lot easier if you qualify through the group stage directly," the former Red Star Belgrade defender told reporters in Perth this week.

"It's been hammered home and I think the boys are well aware of the situation, that there are two games that are separating us from going to a World Cup."

If Australia do beat the Samurai Blue on Thursday, they still face a long wait to find out if they have secured a berth at a sixth straight World Cup finals.

The Saudis kick off in Bahrain some five hours after Australia and Japan, potentially leaving the Socceroos players on tenterhooks well into the early hours of Friday morning.

"If we do get the win, hopefully we will, we are obviously almost there," Degenek added.

"The most important thing is that we win. We can obviously be happy inside and celebrate a little bit, but nothing too major because if Saudi win against Bahrain ... we'll still have to go there and get a result."

With Japan already qualified, Hajime Moriyasu has rested several of his best players and brought in a handful of uncapped youngsters for Thursday's game.

Degenek, who played club football in Japan for Yokohama F. Marinos, did not think that would make Australia's task any easier. "I think it's even harder for us that those so-called stars are out, because the boys that are coming in are going to want to prove to the boss that they should be there at the World Cup," he said.

"So it's not going to be a walk in the park, and they're going to take this as serious, if not more serious, than any other game."

--Reuters--