Because the moment Wallabies general manager Chris Webb called Hoskins' name to wear the No. 18 jersey against England at Twickenham marked the realisation of a childhood dream.

"I was just thinking back, I remember when I was five years old watching my brothers play club rugby," Hoskins told Wallabies Media.

"I turned to my dad on the sideline and said 'I want to play for the Wallabies one day'. Moving over here and playing, I thought that dream had kind of ended."

The 28-year-old London Irish prop wasn't even in the Wallabies squad at the start of the week. Now he joins an Australian side looking to snap a seven-game losing streak against England on Sunday morning [AEDT].

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Lingering concussion symptoms forced the Wallabies' first-choice tighthead props Allan Alaalatoa and Taniela Tupou out following last week's loss to Scotland. Loosehead prop James Slipper "saw the writing on the wall" straight away. The 112-Test veteran knew he'd be the man to fill the gaping void on the other side of the scrum.

Angus Bell would start at loosehead. Tom Robertson could come off the pine as his cover, but that still left a hole on the Wallabies' bench.

Wallabies scrum coach Petrus du Plessis had the answer Dave Rennie was looking for.

So he picked up the phone and called his old London Irish teammate, a man who hadn't been sighted in Australian rugby circles since leaving the Western Force five years ago.

"It came completely unexpectedly. I was just at a friends' house on Sunday and Petrus gave me a call," Hoskins said.

"He gave me a call and said they may need me in camp the next day, but just hold tight and he'd let me know tomorrow.

"I went to training as normal with London Irish on Monday, and then I got ripped out of the gym mid-session and got told I need to go over to Lensbury and get ready for Wallabies camp. It happened unbelievably quick. I had no kit, no nothing.

"I never saw it coming. I just kind of got hit by a wave of emotions and started crying in the team meeting to guys I'd only met a couple of days ago. It means the world to me, this is absolutely wild.

"It's pretty hard to put into words right now. If you'd told me this was going to happen on Saturday night, even after I'd played for London Irish, I would have told you you're kidding. I don't really know what to say right now."

What stands before Hoskins now is arguably the toughest test of his rugby career with just a handful of light training days to prepare for it.

The Wallabies were below their best at set piece against Scotland and now run into a formidable English pack steered around the park by the mercurially gifted Marcus Smith at flyhalf.

Slipper needs no reminder of England's run of dominance over Australia which stretches back to a 3-0 series win in 2016. Players like himself and captain Michael Hooper can use that as fuel.

For many among the rest, the English and Twickenham are relative unknowns. Naturally, more pressure now falls on his shoulders for a side missing two world-class props.

"It's pretty much back to front for me, as a loosehead by trade going over to the other side," Slipper said.

"I've got history at tighthead so it's not too unfamiliar, but at the same time I just needed some time in the seat this week to just have a freshen up.

"The English pack are pretty impressive. We're fully aware of the challenge at hand, we know that's going to be a big part of the game. I've played [tighthead] a couple of times throughout the year.

"I'll put my hand up, I am a loosehead but at the same time I feel like I can back myself at tighthead. One thing I know is I'll do my very best for the team and for the country.

"It's going to be a real challenge and we know that. There's nothing better than playing at Twickenham in front of a packed house of English fans."

SPRING TOUR

Sunday: England v Wallabies at Twickenham, 4.30am.

Wallabies squad: 1. Angus Bell, 2. Folau Faingaa, 3. James Slipper, 4. Rory Arnold, 5. Izack Rodda, 6. Rob Leota, 7. Michael Hooper (c), 8. Rob Valetini, 9. Nic White, 10. James OConnor, 11. Tom Wright, 12. Hunter Paisami, 13. Len Ikitau, 14. Andrew Kellaway, 15. Kurtley Beale. Replacements: 16. Tolu Latu, 17. Tom Robertson, 18. Oliver Hoskins, 19. Will Skelton, 20. Pete Samu, 21. Tate McDermott, 22. Noah Lolesio, 23. Izaia Perese.

England squad: 1. Ellis Genge, 2. Jamie George, 3. Kyle Sinckler, 4. Maro Itoje, 5. Jonny Hill, 6. Courtney Lawes, 7. Sam Underhill, 8. Tom Curry, 9. Ben Youngs, 10. Marcus Smith, 11. Jonny May, 12. Owen Farrell, 13. Henry Slade, 14. Manu Tuilagi, 15. Freddie Steward. Replacements: 16. Jamie Blamire, 17. Bevan Rodd, 18. Will Stuart, 19. Charlie Ewels, 20. Alex Dombrandt, 21. Sam Simmonds, 22. Raffi Quirke, 23. Max Malins.

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