Lopeti Timani will become the Wallabies' newest starting number eight of 2016, replacing the injured Sean McMahon for his first Test start.
Timani came off the bench against Argentina in Perth last month but missed out on the match day 23 for last week's Pretoria Test.
Leroy Houston's 11-year wait for a Wallabies debut is one step closer to ending, with the Reds recruit named on an extended bench for the Twickenham clash.
Wallabies coach Michael Cheika said earlier in the week that Timani had earned the first crack at the number eight spot, in a shift back to a more traditional back row.
“I think that he warrants the opportunity and we want to trial him,” he said.
“We need a player with that profile and he did well when he came on in the first game against Argentina so with a start, he'll a bit more detail he'll have to keep in his head but he'll be fine.
“I think with the profile of the other players we have like the sixes, they're more of the jumping type sixes, that ball carrying eight, that Wycliff Palu style player is something we want to have as well, so won't be able to do both.
“Leroy's quite an abrasive runner as well so. It's a great opportunity to see him step up and how he'll go with the step up.”
The inclusion of Rory Arnold is the only other change to the starting team, making up the tallest Wallabies combination in history, with the 208cm Brumbies lock pairing with 205cm Adam Coleman.
Rob Simmons has been dropped out of the match day squad for the third time this season, after being axed in June and during the Rugby Championship as the Wallabies search for their ideal second row.
In a surprise on the bench, Cheika has opted for both Allan Alaalatoa and Tom Robertson, with 82-Test prop James Slipper the casualty.
Alaalatoa has played tighthead for the Wallabies, but spent much of his Super Rugby season on the loose side of the scrum, giving Australia some handy versatility at scrum time.
This will be the first Test Slipper has missed since last year's World Cup pool match with Uruguay and just the second in which he has played no part since 2012.
Captain Stephen Moore will draw level with George Smith as the fourth-most capped Wallaby, in his 111th Test.
The Wallabies will take on Argentina at Twickenham at 5:30am on Sunday (AEDT) in the final Rugby Championship match.
1. Scott Sio (23 Tests)
2. Stephen Moore (c) (110 Tests)
3. Sekope Kepu (71 Tests)
4. Rory Arnold (4 Tests)
5. Adam Coleman (5 Tests)
6. Dean Mumm (51 Tests)
7. Michael Hooper (59 Tests)
8. Lopeti Timani (1 Test)
9. Will Genia (71 Tests)
10. Quade Cooper (62 Tests)
11. Reece Hodge (4 Tests)
12. Bernard Foley (35 Tests)
13. Samu Kerevi (6 Tests)
14. Dane Haylett-Petty (8 Tests)
15. Israel Folau (46 Tests)
Reserves (one to be omitted)
James Hanson (10 Tests)
Tom Robertson (2 Tests)
Allan Alaalatoa (3 Tests)
Kane Douglas (26 Tests)
Scott Fardy (36 Tests)
Nick Phipps (46 Tests)
Tevita Kuridrani (39 Tests)
Sefa Naivalu (1 Test)
*denotes uncapped player