Mr Fleming confirmed the restructuring Friday, but declined to give details.
"We are commencing a review and realignment of management responsibilities across the organisation; a discussion document will be released later next week.
"Until that time we are unable to comment further," Mr Fleming said.
Association of Salaried Medical Specialists spokesman Dr John Chambers said senior doctors were awaiting details of the restructuring.
"New CEOs in corporate organisations do tend to undertake some sort of restructure a few months after taking over.
"It is clearly a worrying time for some senior managers but they will have been expecting no less.
"It tends to paralyse things with regard to making significant decisions for some months."
Mr Fleming was appointed as chief executive in late January after several months as caretaker chief executive.
