Mapimpi was ruled out of the tournament on Monday when it was confirmed he had a fractured eye socket and would need to return home to South Africa.

While it wasn’t immediately clear, World Rugby confirmed that Am would replace his Sharks teammate in the squad after initially missing out because of injury.

Am was injured in the pre-World Cup warm-up game against Argentina and both he and Handre Pollard missed out on the initial squad because of their injuries.

Pollard replaced hooker Malcolm Marx and played in the 49-18 victory over Tonga to end the Springboks’ pool phase.

Mapimpi was forced to leave the field in the 28th minute after colliding with Tongan scrumhalf Augustine Pulu, with the scrumhalf receiving just a penalty for the collision.

Mapimpi was sent off for a Head Injury Assessment and was replaced by Jesse Kriel.

Afterwards coach Jacques Nienaber said that he had suffered “a blowout fracture of his cheekbone”.

Mapimpi was playing his second game for the World Cup after scoring a hat-trick against Romania in his first outing.

On Monday SA Rugby’s Director of Rugby Rassie Erasmus said it was sad that they had to lose Mapimpi.

"It's sad that something like that happened. It was an accident. He has a fractured eye socket, a blow-out fracture. His eye is swollen and the cheekbone is also fractured I think. I think he's out for four to six weeks.”

Erasmus added that the Boks would miss Mapimpi, even though he had been surpassed by other wingers in the squad. Erasmus paid tribute to Mapimpi’s team ethic and the way he helped other players.

"We will not just miss him as a brilliant rugby player but what he brings to the team. There is a lot of heart, a lot of honesty. He doesn't say a lot but when he says something everybody listens. He trains hard, communicates beautifully on the field while he is really quiet off the field. He never moans if he is not selected and helps the young boys who get selected.”

Erasmus added that if the Boks got to the World Cup final they would fly him back to France to rejoin the team as is tradition. Malcolm Marx would also be flown back after he was forced to leave the camp in week two of the competition with a knee injury. Marx was replaced by flyhalf Handre Pollard.

"If we get to the final we will definitely fly him back to join the rest of us here. The same with the other guys who got injuries and went back to South Africa. It's sad but that's the game of rugby. Those collisions happen,” Erasmus added.

South Africa’s squad after Am’s inclusion

Forwards

Prop

Steven Kitshoff (Ulster – 74 caps, 10 points)

Vincent Koch (Cell C Sharks – 45 caps, 0 points)

Frans Malherbe (DHL Stormers – 61 caps, 5 points)

Ox Nche (Cell C Sharks – 19 caps, 0 points)

Trevor Nyakane (Racing 92 – 61 caps, 5 points)

Hooker

Bongi Mbonambi (Cell C Sharks – 60 caps, 60 points)

Second-row

Eben Etzebeth (Cell C Sharks – 112 caps, 25 points)

Jean Kleyn (Munster – 2 caps, 0 points)

Marvin Orie (Perpignan – 14 caps, 0 points)

RG Snyman (Munster – 26 caps, 5 points)

Flanker

Pieter-Steph du Toit (Toyota Verblitz – 69 caps, 30 points)

Siya Kolisi (captain – Racing 92 – 75 caps, 45 points)

Kwagga Smith (Shizuoka Blue Revs – 33 caps, 25 points)

Marco van Staden (Vodacom Bulls – 12 caps, 0 points)

Duane Vermeulen (SA Rugby – 68 caps, 15 points)

Jasper Wiese (Leicester – 22 caps, 5 points)

Utility forward

Deon Fourie (DHL Stormers – 7 caps, 0 points)

Franco Mostert (Honda Heat – 65 caps, 15 points)

Backs

Scrum-half

Faf de Klerk (Canon Eagles – 48 caps, 44 points)

Jaden Hendrikse (Cell C Sharks – 12 caps, 12 points)

Cobus Reinach (Montpelllier – 25 caps, 45 points)

Grant Williams (Cell C Sharks – 4 caps, 0 points)

Fly-half

Manie Libbok (DHL Stormers – 7 caps, 45 points)

Damian Willemse (DHL Stormers – 31 caps, 36 points)

Handre Pollard (Leicester Tigers - 65 caps, 665 points)

Centre

Damian de Allende (Panasonic Wild Knights – 72 caps, 50 points)

Andre Esterhuizen (Harlequins – 13 caps, 0 points)

Jesse Kriel (Canon Eagles – 61 caps, 60 points)

Lukhanyo Am

Wing / full back

Kurt-Lee Arendse (Vodacom Bulls – 10 caps, 50 points)

Cheslin Kolbe (Suntory Sungoliath – 25 caps, 81 points)

Willie le Roux (Vodacom Bulls – 86 caps, 65 points)

Canan Moodie (Vodacom Bulls – 6 caps, 10 points)

Changes in bold. Players replaced from original squad of 33: Malcolm Marx, Makazole Mapimpi