Pauliasi Manu has been placed on standby for the All Blacks and will join them in London.
Chiefs and Counties-Manukau prop Manu, a specialist loosehead technician, will stay in London while the All Blacksmonitor the fitness of Wyatt Crockett, who has been forced to withdraw from the Rugby World Cup semifinal againstSouth Africa on Saturday (Sunday NZ Time) because of a groin strain.
Having Manu in London gives the All Blacks the option of calling him into the squad if specialist loosehead Joe Moody and the versatile Ben Franks suffer injuries prior to the sudden-death match against the Boks.
Management hope Crockett will return to full fitness and be available to play in the final or the bronze medal game against either Australia and Argentina.
If Manu is rushed into the match-day squad it means the All Blacks will have been forced to select their fourth specialist loosehead during the tournament.
Test centurion Tony Woodcock has already been scratched from the finals because of the hamstring injury be suffered in the final pool match against Tonga in Newcastle.
Crockett started last weekend's quarterfinal against France in Cardiff but had to leave the field in the first half because of his groin problem.
Moody, who had just days earlier been asked to leave Canterbury to join the squad at the training base in Swansea, replaced Crockett and acquitted himself well with his scrummaging and mobility around the park - including a stellar offload that resulted in a try to replacement halfback Tawera Kerr-Barlow.
Moody has been named to start against the Springboks. Franks, who can cover both sides of the scrum, has been promoted to the bench.
They are the only two changes made to the side that thrashed France 62-13 in Cardiff.
All Blacks coach Steve Hansen said management had consulted tournament organisers to clarify the rules before telling Manu to fly to England.
"We have spoken to England 2015 and they have given us permission to bring a guy over, to put him on standby over here because obviously the rules are you have to be here 48 hours (before the game) and you need four props," Hansen said.
"So we have done that, there is a guy on his way over; Pauli Manu from the Chiefs is coming. He is not allowed to train with us. He is allowed to go to the gym and all that sort of stuff.
"It is just a precautionary thing. But we expect Wyatt to be right next week."
Tournament rules state teams cannot pull in outsiders into their trainings. Earlier in the tournament, Wales were accused of breaking the rules by having non-squad members join a training and were fined.
Manu was in good form for the Chiefs this season. In addition to being a capable scrummager he has the reputation for being able to cart himself around the park and complete his duties when cleaning out and carrying the ball.
Hansen said the decision to start Moody ahead of Franks was not difficult.
"There has never been any debate. Ben Franks is a very good prop, he covers both sides. But Joe Moody is a specialist, he showed us he is a very good player and showed us in his performance last week. It is a no brainer."
