Abrasive lock Coleman aggravated his shoulder in training on Thursday and Rory Arnold has moved from the bench to partner Rob Simmons in the starting lineup.
The 21-year-old Rodda, who stands 2.02 metres tall and weighs in at 119 kg, has been brought into the replacements.
Rodda caught was asked to train alongside the Wallabies in Brisbane during their June tests and then elevated to the test squad after just 12 appearances for Queensland Reds.
He made an instant impression on Hooper.
“(I remember) playing him and thinking there’s a big lump of a bloke running at you you haven’t seen before,” said Hooper.
“But then in June, he was walking around in Reds gear and Cheik had him come in and do a bit of training with the guys.
“He ripped in straight away. It’s about taking your opportunity and Rodds, in the wrong gear that day, was taking his opportunity and putting us through our paces.”
The Rugby Championship clash in Dunedin shapes as the most important for the Wallabies this year having lost 54-34 to the All Blacks in Sydney last week, which saw the world champions put one hand on the Bledisloe Cup.
Hooper’s side were pilloried after the All Blacks romped to a 54-6 advantage after 48 minutes, with the biggest criticism being a lack of physicality in the tackle.
The openside flanker said that while players were never truly ready for a test debut, he felt Rodda would grab his opportunity if given the chance.
“You’re never ready,” Hooper said.
“You’re in the best possible position you can be in and you’ve just got to get out there and do what you do.
“He’s just got to get in the jersey and do his thing.”
Cheika, who finalised his bench with Melbourne Rebels loose forward Lopeti Timani preferred over Waratahs flanker Jack Dempsey, added that Rodda had been surprised to learn of his elevation just before their training run on Friday.
“I just told him out on the field go back in and kit up, you’re playing,” Cheika said.
“The look on his face was pretty excited so I am sure he’s going to have a good game on Saturday.
“He’s well worth the investment Izack, he’s got a really good attitude and he’s going to have a great test in his first game for Australia.”
(Reporting by Greg Stutchbury; Editing by Nick Mulvenney/Peter Rutherford)