New Zealand coach John Mitchell has told his players to expect to confront a tough South African team in Saturday's Tri-Nations match in Wellington.

"Looking at South Africa over the last four games, they have been carrying out experiments and I think the team they have chosen to play the All Blacks is a tough one," Mitchell said.

"The main factor in matches between New Zealand and South Africa is that it is always going to be very physical.

"We're all looking forward to the match hugely. Our preparation has been thorough and specific and now is the time to deliver."

The All Blacks beat the Springboks 26-15 on a wet day in Auckland last year but Mitchell, who knows South Africa coach Rudolph Straeuli well, expects a few surprises this time.

Respect

"I know Rudolph Straeuli and have tremendous respect for him. He will have something up his sleeve to throw at us," Mitchell said.

Asked whether he would be prepared to use his replacements on Saturday after leaving them all on the bench against Australia, Mitchell said timing was the important factor.

"In the rain last week it would have been too difficult to bring on a guy to make a difference," he said.

"Also, we have to let the starting XV know we have full confidence in them to go the full 80 minutes. But I would expect to make some changes depending on the match."

Among those waiting in the wings will be Tana Umaga and Jonah Lomu, who sat out the match against Australia and will be anxious to play a part on Saturday.