The match is a part of Nelson Mandela's 90th birthday celebrations, and centre Miguel Avramovic admits it will provide some welcome practice for Phelan's new-look squad.
"The group is great, very united and in a good mood to face this challenge," he said. "The group is integrated between very experienced players, other with less experience and some who are taking their first steps.
"But we all have the same goal and that helps us to get closer and pull in the same direction.
"South Africa are the world champions, very tough opponents who are going through a good spell. Their players are competing now (in the Tri-Nations) and will want to have a good campaign."