Despite being 3-nil up in the America's Cup finals Team New Zealand won't be taking things for granted, former America's Cup winner Brad Butterworth says.

Butterworth told Mike Hosking New Zealand will be working hard over the coming days.

"It looks pretty convincing. I don't want to jinx this thing, things can change. They've got a week that they can change the way that that boat's configured. Little things that New Zealand is doing better.

"You'll see that the guys will be working very hard this week just to try and keep optimising their boat.

"They're sailing their boat differently to the other guys. Obviously their sailing it better and they'll be looking at that, trying to learn something and lift their game," Butterworth said.

LISTEN ABOVE AS FORMER AMERICA'S CUP WINNER BRAD BUTTERWORTH SPEAKS TO MIKE HOSKING