Australia have made three injury-enforced changes for the second Test against France in Melbourne on Saturday.
Hooker Stephen Moore (knee), lock Sam Carter (ankle) and No 8 Wycliff Palu (ankle) have all been ruled out.
Medical staff have taken a cautious approach with Palu, who is expected to return for the final game of the series in Sydney.
Replacing Moore is Tatafu Polota-Nau, who produced a devastating 76-minute performance in Australia's 50-23 victory in the first Test.
Horwill comes in for Carter while Force workhorse Ben McCalman continues his breakthrough 2014 campaign with selection at No 8.
Three players are also in line to make their Test debuts with Force hooker Nathan Charles and Rebels pair Laurie Weeks and Luke Jones all chosen on the bench.
Wallabies – 15 Israel Folau, 14 Adam Ashley-Cooper, 13 Tevita Kuridrani, 12 Matt Toomua, 11 Nick Cummins, 10 Bernard Foley, 9 Nic White, 8 Ben McCalman, 7 Michael Hooper (c), 6 Scott Fardy, 5 James Horwill, 4 Rob Simmons, 3 Sekope Kepu, 2 Tatafu Polota-Nau, 1 James Slipper.
Subs: 16 Nathan Charles, 17 Pek Cowan, 18 Laurie Weeks, 19 Luke Jones, 20 Scott Higginbotham, 21 Nick Phipps, 22 Kurtley Beale, 23 Pat McCabe.
Photo: Chris Hyde/Getty Images