It is estimated around 10,000 fans could attend a fight at Vector. Eden Park has a seated capacity of 48,000 but could probably take another 10,000 in temporary seating on the field itself.
Mt Smart's capacity for a rugby league game is about 30,000 but it could also squeeze in another 10,000 in temporary seating.
It will be intriguing to see if the bout would sell out an outdoor stadium. The other issue will be the weather.
Auckland's climate in December is forever changing with rain a potential any day of the month.
However, outdoor fights at major venues are hardly new - even in this part of the world.
Australian Jeff Fenech fought Azumah Nelson for a world title at football ground Princes Park in Melbourne in 1992. How the event was protected from potentially inclement weather will be the template for Duco to follow.
Chief Executive of Heart of the City Viv Beck said the fight was a very exciting opportunity for Auckland, and New Zealand.
"It's certainly putting New Zealand onto the world stage in another new and exciting way," she said.
Ms Beck said the city's only got a short time to prepare for the fight, but will be up for it.
"We're very familiar with running major events in the city and we have hosted major events," she said.
"Planning will have to move fast, but it's definitely an opportunity we can't let go by."
