New Zealand captain Stephen Fleming says he has doubts about the portable, drop-in wicket that will be used in Tuesday's second one-day international against South Africa.

Fleming scored an unbeaten 115 in last month's one-dayer against Pakistan at Christchurch's Jade Stadium and he said the natural pitch used then was the best of the domestic season.

"The wicket's changed to a drop-in and that's a big change," he told reporters on Monday.

"While we all like to think and hope it's the same type of surface we had with the natural wicket, you've got to be a little bit apprehensive of a drop-in at this point because they are in their early stage of development.

"It is a bit frustrating that we can't entirely rely on a good surface. But it's part of the crossover of the two (cricket and rugby) seasons and groundsmen are left with no choice with the Super 12 coming up, and we've got to accept that."

Four days after New Zealand play South Africa, the Canterbury Crusaders rugby team will run out against the New South Wales Waratahs.

The pitch for the first game of the six-match series, won by South Africa by five wickets with two balls to spare in Auckland on Friday, was also of the portable variety and was slow and of variable bounce.

Fleming said after the Auckland match that the teams were not far apart.

"They (South Africa) are a very good side but once again it came close. What we've got to find is that five percent that's going to make the difference," said Fleming.

"We can't really afford to go 2-0 down and we have to improve in certain areas. The coach (John Bracewell) said we were a little ring rusty from the domestic cricket we've been playing, so we have to look for an improvement in the field and that could be the difference.

"They fielded very well in Auckland and stopped us getting the 20 extra runs we really needed that night."