The Mexicans have stumbled through a dismal qualifying campaign, limping to fourth place in the CONCACAF federation for a last-gasp chance to make it to Brazil with a two-legged tie against the All Whites.
Herbert, who guided New Zealand to an unbeaten run in the group stages of the last World Cup in South Africa, said his charges would not underestimate Mexico, who at 24th in the world are ranked 55 places above his team.
"They're a hell of a good team and on their day they could beat anybody at home, that's the challenge we face," he said.
But he said the Mexicans, who have not missed the World Cup since 1990, showed they were vulnerable during their turbulent CONCACAF qualifying campaign.
In a string of results that left their fans angry and disillusioned, Mexico won only two of 10 games, scored just seven goals and sacked three coaches before appointing Miguel Herrera for the New Zealand play-off.
Herbert said he attended Mexico's 2-1 victory over Panama at the Azteca Stadium in Mexico City last month and felt the home side struggled before a spectacular bicycle kick from Raul Alonso Jimenez delivered a late winner.
"I sensed a vulnerability, you really sensed the nervousness of the players, the uncertainty," he said, pointing out the team also lost 2-1 to Costa Rica a few days later.
Herbert said Mexico looked more confident when they defeated Finland 4-2 in a friendly last week but the players knew they were not competing for a World Cup spot.
He said it would be a different story in the first leg of the play-off at the Azteca on 13 November, when the home crowd at the 105,000-capacity stadium would be expecting success. The second leg is a week later.
"It (the Finland friendly) was a great chance for their players to go out and express themselves," he said.
"Whether or not they can take that into a pretty hostile environment where the pressure is 100 per cent going to be on them, I do have my doubts."
Herbert, whose teams are known for their dour defence, said the All Whites would take the same approach against Mexico as they adopted against Bahrain to qualify for the 2010 World Cup.
New Zealand ground out a 0-0 draw in the away leg before winning 1-0 at home.
"So much depends on that first leg, as it was against Bahrain," Herbert said. "That really set us up for a good crack at home and hopefully we can be in that same position this time."
He does not expect his players to be overawed by the atmosphere at the Azteca Stadium.
"I think they'll be very controlled. There's a real anticipation and excitement in the group about going there to play."