After a narrow defeat to South Africa and victories over Samoa and Namibia, Wales would need to be heavily beaten by Fiji to miss out on a likely quarter-final showdown with Ireland.
While it appears mission accomplished already, Wales have often struggled against the underdogs - particularly during World Cups - and drew 16-16 with Fiji at the Millennium Stadium last November.
And after admitting to underestimating lower ranked nations in the past, Gatland insists he has a squad strong enough to rotate without risking victory in Hamilton.
"When you are building up for a World Cup, you have to look at certain games where you try to develop some depth and give youngsters an opportunity," he said.
"Sometimes in the past, against Fiji and even in the Six Nations against Italy, I've been guilty of that and nearly come unstuck.
"But you have to believe in the pathway and what you want to achieve and hopefully turn up at this tournament in good shape and with some depth as we have that at the moment.
"I think it's the youngsters who have been performing incredibly well for us.
"It's also nice that after injuries some of the more experienced players have been coming back and fighting for position."