Both will be tempted to send their opponents in to take advantage of expected early life in the pitch but both have had their tactics backfire spectacularly after calling correctly in recent matches.

The two results in the newly rebuilt stadium will not have helped them make up their minds.

South Africa hammered a massive 356 for four when they were sent in by West Indies Tuesday, winning by 67 runs, while New Zealand made a disastrous start after Fleming decided to bat against Sri Lanka Thursday, going on to lose by six wickets.

Both of South Africa's defeats in the tournament came after Smith opted to field first when they lost by 83 runs against Australia and when they suffered a shock 67-run setback against Bangladesh.

The pitch for the New Zealand-Sri Lanka match was slower and drier than it was when South Africa played two days earlier, adding to the uncertainty for the captains.

New Zealand were pace-setters in the Super Eights phase, winning their first four matches and topping the table on run rate before they lost against Sri Lanka.

But they have a tough run-in, with the match against South Africa followed by a clash with defending champions Australia here on April 20, which could mean they get stuck on eight points.

"We have had a good run so far at the tournament," said Fleming.

"Against Sri Lanka was the first time we were really tested and put under pressure and we didn't come through. It is disappointing but we are a better side than that."

South Africa, meanwhile, will move to eight points if they win Saturday but because they have the worst run rate of the semifinal contenders they will probably need to win their final match against England in Barbados Tuesday to ensure they do not risk being squeezed out in the event of a tie on points.

South Africa's batting was spectacular against the West Indies, with opener AB de Villiers making an explosive 146, backed up by half-centuries by Jacques Kallis, Herschelle Gibbs and Mark Boucher.

But there have been question marks about the South African bowling, with opening pair Shaun Pollock and Makhaya Ntini yet to make significant inroads at the start of an innings.

New Zealand's Shane Bond is the fastest bowler at the World Cup and his strike bowling was a key element of his team's success in the opening weeks.

For the rest, New Zealand have steady seam bowlers and the left-arm spin of Daniel Vettori.

It is likely that off-spinner Jeetan Patel will come into the side in place of seamer Mark Gillespie.

Fleming said it had been a 50-50 decision between the two bowlers.

Given the way the Sri Lanka match went, and South Africa's perceived weakness against spin, Patel is likely to get the nod.

New Zealand may also ponder whether to pick Ross Taylor or Hamish Marshall to fill the number three batting position. Taylor was the preferred choice but missed three matches because of injury and failed to score on his return against Sri Lanka.

South Africa's ability to bounce back against the West Indies after losing to Bangladesh gave the side renewed confidence and Smith said after the match that his team had resolved to play positive, attacking cricket after being tentative against Bangladesh.

SQUAD
NEW ZEALAND: Stephen Fleming (capt), Peter Fulton, Ross Taylor, Scott Styris, Craig McMillan, Jacob Oram, Brendon McCullum, Daniel Vettori, James Franklin, Jeetan Patel, Shane Bond.

SOUTH AFRICA: Graeme Smith (capt), AB de Villiers, Jacques Kallis, Herschelle Gibbs, Ashwell Prince, Loots Bosman, Mark Boucher, Shaun Pollock, Andrew Hall, Andre Nel, Makhaya Ntini.

Umpires: Mark Benson (ENG) and Daryl Harper (AUS).