And the inspiration for Sio's rugby career will be sitting in the Twickenham stands 12 years after dad David gave up his tickets to the World Cup final so his son could watch the Wallabies play. Sio is the only change to the line-up for the mouth-watering final against New Zealand on Saturday (Sunday morning AEDT).

The chance to rise to World Cup glory will add another chapter to the Sio family history that has followed the tournament since David played for Samoa 24 years ago. The story of Sio's name is well told among rugby circles. David named his son Scott after Samoa lost to Scotland at the World Cup in 1991.

Twelve years later David secured tickets to the 2003 final between the Wallabies and England, but gave his tickets to his rugby-mad sons while he stayed home to watch the game. "This is his dream, it's part of our dreams and it's great to see him here," David said.

"It's a different kind of feeling being here, it's hard to describe. It's been quite a journey and we're incredibly proud of Scott. I had tickets to the final in 2003, one of the uncles turned up so I gave my ticket to him and he went with my wife and the two boys [Scott and Patrick]. They all came back home sad because Jonny Wilkinson kicked that drop goal and Australia lost. You hope one day your sons will be on that World Cup stage.

"It's a bit emotional now, the feeling is hard to describe. I guess Scott just has to seize the moment."

The Wallabies have kept largely the same starting line-up throughout the World Cup, and coach Michael Cheika is putting faith in his starters to win one more game. Israel Folau keeps his place at fullback despite some form struggles while David Pocock has full recovered from a calf injury and Scott Fardy (hip) and Matt Giteau (groin) are fit to play.

Sio's return is a massive boost for the Wallabies' scrum after it struggled against Argentina last weekend.

The ACT Brumbies front-rower is a crucial inclusion to match the All Blacks' pack, with Wallabies' 1991 World Cup-winning coach Bob Dwyer arguing last week he was more influential than Pocock.

The Wallabies conceded four scrum penalties without him in the semi-final last weekend after Sio helped lay the foundation for a rebuild set piece.

His name provides the inspiration to his World Cup campaign. He was born when David was playing at the 1991 tournament and David let the rugby Gods decide his name. If Samoa won their quarter-final against Scotland, his son would be named Manu. But history shows Scott carries his dad's story wherever he goes.

David will be beaming with pride when he sits in the stands, but he recalls the days when he would have to pour water on his "cheeky" son as a punishment. "The boys were always trying to get away with things. You'd send them for a run around the block and he'd go and have a sleep down at the park," David said. "You'd turn up 30 minutes later and pour some water over him. He'd be hiding in the park for a bit and then you'd find him to make him run back."

Sio says his dad has been the biggest influence on his rugby career. He has a chance to write his own story as the Wallabies aim to lift the Webb Ellis Cup for the first time since 1999.

And David has some simple advice: "He's just got to have fun. You just try to impart that it's the spirit in the team that carries you through the big moments.

"For us it was overwhelming [in 1991], we surpassed everyone's expectations. And this is one of those moments that will live with you forever. "

WALLABIES TEAM: 15. Israel Folau, 14. Adam Ashley-Cooper, 13. Tevita Kuridrani, 12. Matt Giteau, 11. Drew Mitchell, 10. Bernard Foley, 9. Will Genia, 8. David Pocock, 7. Michael Hooper, 6. Scott Fardy, 5. Rob Simmons, 4. Kane Douglas, 3. Sekope Kepu, 2. Stephen Moore, 1. Scott Sio. Reserves: 16. Tatafu Polota-Nau, 17. James Slipper, 18. Greg Holmes, 19. Dean Mumm, 20. Ben McCalman, 21. Nick Phipps, 22. Matt Toomua, 23. Kurtley Beale.