All Black assistant coach Wayne Smith has admitted that the New Zealand selectors do not know what their best XV is at the moment, but added that they were not losing too much sleep over it.

The All Blacks are busy gearing up for their opening Tri-Nations encounter with the Springboks in Wellington this weekend and the clash with their injury-ravaged rivals may just be a prime opportunity to separate the wheat from the chaff ahead of the World Cup.

New Zealand's player depth has been both a strength and a weakness in the past as the All Blacks have battled at times to strike a balance between competition for places and continuity in the team with head coach Graham Henry coming in for some serious criticism following the last World Cup in France in 2007.

However, this does not seem to bother Smith who is delighted at the fierce contest to wear the black jersey at the moment.

He told NZPA: "We don't really know what our top XV is at this point. There's a lot of competition, a lot of guys playing for spots and that's a good way to be.

"We're trying to get everyone in the squad competitive and I think you saw that at the weekend [against Fiji]. We've got a lot of outside backs who are injured - all the outside backs that played on the weekend were great and that's put a lot of heat on and that's what we're looking for," he added.

The selection of the team this weekend will be telling, skipper Richie McCaw has been running at No.8 in training this week and there is much speculation that he will start his first Test at the back of the scrum in order to give Adam Thomson the opportunity to prove himself as the ideal back-up at openside flank for the World Cup.

Smith confirmed that while the task of beating South Africa this weekend was obviously a priority, the coaching staff do have one eye on the World Cup as they try to find the formula to win the global showpiece event on home soil later this year.

"We've got an eye on the World Cup. Obviously you've got to have your planning in place, but we really want to win. We want to win Tri-Nations, we want to retain the Bledisloe Cup and we want to put a marker in the sand too," he said.

If the All Blacks training sessions are anything to go by, another player that is likely to get an opportunity to start this weekend is lock Sam Whitelock who looks set to replace Jarrad Hoeata in the second row next to Ali Williams as his Crusaders teammate Brad Thorn is given a rest.

Whitelock said that the intensity in the camp is very high at the moment, even when the players are meant to be relaxing.

"The energy and excitement is there for everyone. All the guys here are very competitive, if they weren't they probably wouldn't be here. That goes through playing cards in down time or on the training field," he said

McCaw was critical of his team's work at the breakdown against Fiji, and Whitelock confirmed that they have been working hard on that aspect of their game this week.

"It's fair to say we were a little bit rusty there [at the breakdown] so we've done a bit of work and no doubt we'll carry on doing that over the weeks. It'll be a constant thing we'll have to work on," said Whitelock.