"It's incredibly tough," Vicelich said. "It's not the World Cup but the standard is so high and they are all top teams. We have to be realistic.
"The All Whites will need everyone playing and performing at their best level, otherwise it will be very difficult."
Vicelich is also concerned about the absence of injured West Ham defender Winston Reid.
"He brings so much and you can't replace that," Vicelich said. "So that's unfortunate. But it is an opportunity for someone else and the back three has done well lately."
Vicelich emphasises the tournament has benefits that stretch far beyond the next few weeks in Russia.
"It's a great opportunity, with the warm-up games and all the time together," he said. "It's a vital time, to build camaraderie and mould the tactics."
New Zealand at the Confederations Cup
1999 (Mexico): v United States 1-2, v Germany 0-2, v Brazil 0-2.
2003 (France): v Japan 1-3, v Colombia 1-2, v France 0-5.
2009 (South Africa): v Spain 0-5, v South Africa 0-2, v Iraq 0-0.