Denyer reportedly has full movement of his limbs, but was in considerable pain before receiving pain relief.
He was to have been the star attraction of the monster truck show.
It is not yet clear if yesterday`s accident will prevent him from competing in Australia`s biggest motor race next month, the Bathurst 1000.
"The injuries were thought to be serious, and he is being kept in hospital for the time being," Seven news and current affairs chief Peter Meakin said.
"But from what we`ve since been told we believe he is going to be OK."
Meakin said Denyer was not on duty for Seven but competing in a monster truck sport event.
"Grant has been involved in the sport and motor racing for some time," Meakin said.
"But this caught us by surprise and and we`re just hoping and praying the injuries are not as serious as first thought."
Denyer - who could not be reached for comment - was expected to recover enough for an interview on Sunrise today.
- with The Daily Telegraph`s Marcus Casey
