Video report by ITV News Sport Correspondent Amy Lewis
Anthony Watson spent his childhood playing rugby with his two brothers in their Middlesex garden, pretending to be in a World Cup Final. On Saturday, he will be doing just that for England.
Rugby runs in the Watson family.
His father, Duncan, played for Saracens and now all three of his sons play professionally.
Eldest son Marcus, 28, who plays for Wasps, told ITV News: “When we were younger, Jason Robinson was our favourite player.
"After that (2003) World Cup Final we were in the garden playing rugby with each other pretending to be Jason Robinson, and it’s crazy to think there are going to be kids playing in their garden pretending to be Anthony Watson.”
Callum, who at 22 is the youngest of siblings, plays semi-professionally for Chinnor Rugby Club in Oxfordshire.
He told ITV News he couldn’t believe his brother would be lining up in the final on Saturday.
"Words can't really describe that, a World Cup final, it’s a once in a lifetime thing really, and I can’t wait. We’re all so proud as a family to be here,” he said.
Anthony Watson's story is all the more impressive because he ruptured his Achilles last year and was sidelined for 13 months, with prospects of being fit for the World Cup looking bleak.
His father Duncan told ITV News: "He’s a boy who if he wants something he will do it.
He is very determined, and if you look at what he’s done because of his Achilles, and how he’s come back, he’s been pretty extraordinary.
"But I don’t think people realise how hard he’s actually pushed himself to get where he is now.”
On Saturday the Watson family will be sitting in the stands, but before then, they have a nerve-wracking 24 hours to fill.