Tri-Nations - South Africa's preparations for Saturday's Tri-Nations clash with New Zealand have suffered a double set-back with the withdrawal of loose forwards Pierre Spies and Juan Smith through injury.

Number eight Spies (pictured) misses the Durban clash owing to a knee injury suffered in training on Thursday and is replaced by former skipper Bob Skinstad.

Danie Rossouw comes in for Smith after the flanker failed to recover from a thigh injury sustained last week in the narrow win over the Wallabies.

While Skinstad and Rossouw are both able replacements, the Springboks could miss the speed and cover provided by Spies and Smith.

Spies, in particular, has been in excellent form recently, and scored two tries against in the second-Test rout of England.

Springboks coach Jake White also has injury concerns over outside centre Jaque Fourie, who missed training on Tuesday and Wednesday.

If Fourie fails to recover in time, White can call up Wynand Olivier or Frans Steyn, the hero against Australia after kicking two later drop goals to secure victory.

White has already been forced to withdraw skipper and hooker John Smit and prop Gurthro Steenkamp, while wing Bryan Habana and scrum-halves Fourie du Preez and Rickie Januarie are longer term absentees.

Revised South Africa team: 15-Percy Montgomery; 14-Ashwin Willemse, 13-Jaque Fourie, 12-Jean de Villiers, 11-JP Pietersen; 10-Butch James, 9-Ruan Pienaar; 8-Bob Skinstad, 7-Danie Rossouw, 6-Schalk Burger, 5-Victor Matfield (capt), 4-Bakkies Botha, 3-BJ Botha, 2-Gary Botha, 1-Os du Randt.

Replacements: 16-Bismarck du Plessis, 17-CJ van der Linde, 18-Johann Muller, 19-Pedrie Wannenburg, 20-Michael Claassens, 21-Wynand Olivier, 22-Frans Steyn.