But finally back on home soil for a match delayed by a week, Rennie, who was "bloody angry" about the rescheduling, said his players were ready to be better.
"We were fired up when we got the initial news, but there are enough motivating factors heading in to this test without talking about the All Blacks," he said.
"We have to be a hell of a lot better. We are a lot better side that scoreline suggested. But I can say whatever here - it's what we do on the park.
"I can assure you the team was hurting. We went through a review and there was a lot of honesty throughout that. We've made a couple of selection changes as well and I'm confident we will have a better defensive performance."
Rennie made another five changes to his bench, dropping four more players as the Wallabies look to salvage something from the third and final game, having already lost the Bledisloe Cup, and replicate the 47-26 victory Australia achieved in the only other match the teams have played at Optus Stadium.
Young playmakers Noah Lolesio and Tate McDermott will get another shot at the All Blacks as a starting pair. Rennie said Cooper, who was brought into the squad amid injuries to other playmakers and to help educate fly-half Lolesio, was "close to selection" before being overlooked.
The imminent return of Queensland star James O'Connor for the upcoming Rugby Championship is now likely to push the 33-year-old Cooper back to Japan. But Rennie said he had "no update" on whether the veteran would remain with the Wallabies beyond this week.
Despite picking Kerevi, who has been playing in Japan, and with a relaxing of the Giteau Law imminent, Rennie said there had to be caution in opening the floodgates to overseas players.
"We've had lots of discussions around it. What's important is we are doing what we think is best for rugby in Australia," he said. "We don't want to go wholesale and have lots of players to pick from overseas. I think it will have an effect on domestic rugby. Based on the Covid situation, we have had a little bit of leniency around that."
Izack Rodda will come off the bench to play his first match for the Wallabies since the 2019 World Cup.
Both Hunter Paisami and Lukhan Salakaia-Loto have left the squad to be with their respective partners ahead of the imminent birth of children.
Folau Fainga'a is also set to play his first test of 2021, named at hooker for Brandon Paenga-Amosa who has a neck injury.
Wallabies:
Tom Banks, Andrew Kellaway, Len Ikitau, Samu Kerevi, Marika Koroibete, Noah Lolesio, Tate McDermott, Rob Valetini, Michael Hooper (c), Lachlan Swinton, Matt Philip, Darcy Swain, Allan Alaalatoa, Folau Fainga'a, James Slipper
Reserves: Lachlan Lonergan, Angus Bell, Taniela Tupou, Izack Rodda, Pete Samu, Nic White, Reece Hodge, Jordan Petaia