Ireland scrum coach Greg Feek will have a big say on whether Tadhg Furlong will be retained or Mike Ross returned for the final test.
"There were a lot of nerves coming over here, particularly with the reputation and the size of the South African pack," he said. "Obviously, Tadhg's been on our radar for a while and I think he did very well from where we were sitting (in Johannesburg)."
The generosity of Ross towards Furlong at Leinster has often been noted by the younger man.
It has led to the accelerated progress of the 23-year-old and a debt of gratitude owed to the veteran.
"They spend a lot of time together in the club," said Feek.
"It's important for a young player to have a mentor that's been there and done that."
Certainly, Feek has made it no secret Ireland are glad to see the back of Duane Vermeulen.
The Springbok number eight, due to an elbow injury, is joined by lock Lood de Jager (calf) and back-up prop Trevor Nyakane (ankle) in being ruled out for Port Elizabeth.
"He's one of the most powerful loose forwards in world rugby," he said.
"Sometimes you spend an extra bit of time working out how to stop someone like that, whether it's ball carry, tackle and particularly when he's on the ball.
"He's hugely strong and I think the players around him would get boosted by having him there."
This will probably lead to the introduction of the impressive Warren Whiteley from the start.
"We're certainly in awe of some of the talent that is available (to the Springboks)," added Feek.