Luke Morahan will be 13th man for the Aussie Sevens in the Sydney 7s while Australian fans will have a firsthand look at Trae "Quadzilla" Williams in their home tournament.
Morahan has been training with the side this week, released from club side Bristol Bears during the Six Nations break, and is hoping to push for a Tokyo spot.
Ben O'Donnell is the big absentee in the lineup after suffering a knee injury in last weekend's Hamilton Sevens.
Aussie Sevens coach Tim Walsh said Williams would bring X-factor to their team but after failing to see him in space in his two previous tournament appearances, in Dubai and Cape Town, it was up to the team to create room to show his wheels.
"To have the fastest player in world rugby there, ready to ignite the engine is pretty special," Walsh said on Thursday at Bankwest Stadium.
"We have to as a team have to manipulate it and work out a way we can put him in that space, and allow him to use his point of difference.
"So we have been working pretty hard and Trae certainly has been and he has earned his spot here for further push his case for selection going forward.
"We haven’t got him into space. Sevens is a magnified game and it can be quite complicated, especially for someone coming in pretty fresh.
"To have speed in sevens is a huge asset and that’s something we have to work out."
Walsh said there was still a chance of Morahan getting a run in the Sydney Sevens, with many teams using their 13th man during tournaments.
World Rugby rules allow for the 13th man to replace an injured player during the tournament.
"I was tempted (to pick him in the 12) but we have to make sure Luke is in the right position for it," Walsh said.
"The biggest thing was to get him here, have a bit of a training camp and if we get to use him, we get to use him."
Williams, who switched from athletics to rugby last year, said his experiences in Dubai and Cape Town had helped him settle into life as a footballer.
"Going over there and learning the game, and being able to get on at the first World Series tournament, was really good and it taught me a lot about the game," Williams said.
"Coming into this weekend I am excited and keen for it."
The Australians meet Japan and Scotland on Saturday and then play against the USA on Sunday morning, setting up another potential showdown between "Quadzilla" Williams and Carlin Isles, the electric USA speedster.
They've had plenty of off-field attention but are yet to go toe-to-toe on the field despite two previous encounters.
"It will our third game on Sunday and it'd be good to get a match-up with him," Williams said.
"Last game we didn't really match up with each other, so it would be good to see."
The Sydney 7s kicks off at Bankwest Stadium on Saturday February 1 and runs until Sunday February 2. Buy tickets here.
IN: Trae Williams, Luke Morahan (13th)
OUT: Ben O'Donnell, Rod Davies
Australian Men's Sevens for Sydney 7s
1. Henry Hutchison, Randwick, 29 caps
2. Dylan Pietsch, Randwick, 15 caps
3. Jeral Skelton, Brothers, 17 caps
4. Lewis Holland (vc), Queanbeyan, 49 caps
5. Lachie Miller, Randwick, 9 caps
6. Joe Pincus, Easts (Sydney), 9 caps
7. Josh Turner, Manly, 3 caps
8. Jesse Parahi, Norths (Sydney), 47 caps
9. Trae Williams, 2 caps
10. Nick Malouf (c), University of Queensland, 37 caps
11. Maurice Longbottom, Lloyd McDermott Rugby Development Team, 17 caps
12. Lachlan Anderson (vc), Eastwood, 24 caps
13. Luke Morahan, Bristol Bears, 6 caps
Saturday February 1
Australia vs Japan, 12:19pm
Australia vs Scotland, 5:46pm
Sunday February 2
Australia vs USA, 11:29am