Reports from the Sydney Morning Herald say that senior executives, Ahmed Fahour, Lynne Peacock, George Fraziz and John Hooper will all be strengthened in their positions.
When Mr Stewart retires from the job he has supported the calls to promote from the inside.
The bank announced record $4.6 billion annual profits on Friday and Mr Stewart felt there was a depth of talent behind him.
Speaking to the newspaper he said he hoped his successor came from beneath him.
"The chairman and the board will be very disappointed if it's not an internal candidate," he said.
He announced that he had achieved all the aims that would set NAB to full financial health and he felt the bank was now settled on a path of growth.
Michael Ullmer, now deputy chief executive, will not be going for the position but would rather play a key role in the handover of power.