Will Genia... inspired Aussies to WCup final.

Will Genia may be the smallest player in the Australia rugby team but the scrumhalf remains one of the most important.

Every great rugby team needs a great halfback and it is no coincidence that Wallabies' inspiring run to Saturday's World Cup final against New Zealand has come at the same time as Genia's own return to form.

At his best, he ranks among the world's top scrumhalves. Plucked from the Queensland reserves bench straight into the Australia team in 2009, he was an instant hit for a Wallabies side searching for a long-term replacement for George Gregan.

In 2011, Genia scored the winning try when Australia beat New Zealand to capture the Tri-Nations title for the first time in a decade, and was later short-listed for world rugby's player of the year.

But injuries and some inconsistent play combined to stall his progress before he bounced back this season at the perfect time, motivated by the prospect of trying to win the World Cup.

"It's one of those things – you want to go out and perform to the best of your ability on the training field and make sure you get the job done," Genia said.

"I think that's been a big thing that's been driving me through this tournament but also just being a part of this group."

Born in Papua New Guinea but raised in Brisbane, Genia became fascinated with the World Cup as a teenager when he watched the 2003 final, which Australia lost to England in extra time after a last-gasp Jonny Wilkinson drop goal.

He played at the 2011 World Cup, captaining the Wallabies in their pool game against the United States, but the memories of 2003 still drive him.

"I remember watching it, I was at school. It was obviously heartbreaking for us Aussie fans at the time. Jonny Wilkinson kicking that drop goal," he said.

Saturday will mark the first time since 2003 that the Wallabies have been in the final and it will also be a poignant occasion for Genia. The 27-year-old, capped 65 times, is leaving his homeland after the tournament to play club rugby in France.

Although he could still be picked for Australia under new rules allowing players with 60 or more appearances to play overseas, Genia is not counting on being selected again.

"For me, I kind of see this as my last test for Australia and I want to make the most of it and really enjoy it," he said.