Wellington Phoenix - with All Whites regulars Mark Paston, Ben Sigmund, Tony Lochhead, Tim Brown and Leo Bertos - has forged an impressive unbeaten run of 13 A-League games at Westpac Stadium in just over 12 months.

That, along with a packed house, is something Nelsen feels will work in the national team's favour as it looks to reach the World Cup for the first time since 1982.

"Obviously the 35,000 Kiwi fans are hopefully going to be screaming and chanting and going crazy come Saturday and I think that's going to be a huge advantage for us," the Blackburn defender said.

"I think also for the Wellington boys it's their home field and they have got a formidable record there at home. They know every blade of that grass and those boys are going to be key for us. There are some great advantages for us.

"Obviously the cold hard facts are that Bahrain have played 20-odd games and are extremely well funded. That's life but we're extremely positive heading into this game."

Bahrain coach Milan Macala has said with the teams locked at 0-0 from the first leg and with the away goal rule in place that he believes one goal might be enough for his team to take the spoils in Wellington.

But when Nelsen was told that at Tuesday's packed press conference his reply was swift: "Well, not if we score two."

He added: "Of course they will be having their game plan and we've got ours.

"But I've played in enough big games like this where in the end most conceptions of what they think the game is going to turn out like don't materialise like that.

"All I know is that it will be a fantastic entertaining game full of pressure and intensity and let's just see who takes the opportunities."

Nelsen was also in no doubt as to just how big Saturday's match really is and what it would mean for New Zealand to qualify for the World Cup.

"There are more people watching that than the Olympics. There are more people watching that than anything on the sporting planet," said the All Whites skipper.

"To get to a sporting event like this, in general I think most people understand that it's fairly big. In terms of playing in it and for coaches and management team it's the absolute pinnacle in all sport. There is nothing bigger.

"This is bigger than the Olympics 100m final if you get to it and potentially go on. If you win the World Cup in football there is absolutely nothing on this earth bigger than that."