New Zealand will look to set a benchmark of high standards when they launch their IRB Junior World Championship title defence in Japan tonight.

The Dave Rennie-coached Under-20 team kick-start their campaign against South American minnows Uruguay in Nagoya.

The action then heats up when New Zealand plays Ireland next week.

While New Zealand are huge favourites going into the clash against Uruguay, Rennie said that was no cause for complacency or over-confidence.

With little footage available of Uruguay in action, Rennie the priority for New Zealand was to set their own standards tonight; both on the scoreboard and in their overall skills execution.

"We know very little," a straight-up Rennie said.

"So really, we are going to focus on ourselves and try and get our systems right and set some standards, some stats for what we want to achieve out of the game.

"They will be very similar to an Argentinian side. South Americans are very passionate.

"I know they will be very excited, so they won't be a walkover."

Rennie confirmed his team for the Uruguay clash on Wednesday night.

The starting line-up includes Guildford and Blues player Winston Stanley.

Manawatu's Aaron Cruden will captain the side which also includes Southland Stags player Robbie Robinson who has been named on the bench.

But it is likely that significant changes will be made for Tuesday's must-win clash against Ireland, with the winner likely to win their pool and qualify for the quarter-final stage of the tournament.

"It is pretty important that you use the whole squad here," Rennie said.

"It is just too difficult to churn out the same 15 guys five times in 17 days. It is a test of your depth."

Meanwhile, the IRB has confirmed a new format for the Junior World Championship, with the number of participating teams being reduced from 16 to 12 in 2010.

This restructure, approved by the IRB Council, means that the top 12 teams at this year's tournament in Japan will automatically qualify for the 2010 tournament in Argentina.

The bottom four will participate in regional qualifying structures for the second-tier IRB Junior World Rugby Trophy 2010.

"The IRB is committed to increasing the overall competitiveness of the game and our age-grade tournament strategy is very important in achieving this," IRB head of development and performance Mark Egan.

"The IRB Junior World Championship has proven extremely successful in providing the next generation of international players with a platform to develop their skills in a format that replicates a Rugby World Cup environment.

"However, with 550 players and team staff, the tournament is also a large one and in the current economic climate it is prudent to take measures to relieve the financial pressure on both the IRB and the hosting Union, while maintaining the high standard of the tournament.

"The new format for the IRB Junior World Championship will optimise the opportunity for competitive pools matches, while the regional qualifying tournaments and IRB Junior World Rugby Trophy will continue to provide a strong global age-grade player development pathway."

With the hosts qualifying automatically, should Argentina finish outside the top 12 ranked teams, then they will join the top 11 ranked teams in qualifying for the tournament.

The new tournament structure will comprise three pools of four teams with the winner of each progressing to the semifinals, along with the best placed runner-up.

The remaining teams will play for a positional ranking. Unions were notified of the structural change last month.