South Africa have been dealt a huge blow ahead of their Rugby World Cup semi-final against Wales, with Cheslin Kolbe ruled out due to injury.

Livewire wing Kolbe tweaked the ankle injury that kept him out of the pool match against Canada when he returned to the team for the last-eight victory over Japan.

Sbu Noksi has consequently moved into the starting line-up for Sunday's match at Yokohama, the sole change to the 23 selected by Rassie Erasmus.

"It's disappointing not to have Cheslin available as he has been brilliant for us since we first called him up last year," said head coach Erasmus.

"But we really rate Sbu and he will slot straight in. I am as excited to see what he can do as I would be if Chessie were playing. Sbu has been very close to selection as it is."

Nkosi, who has scored eight tries in 10 Test appearances for the Springboks, featured in pool matches against Namibia and Canada, touching down against the latter.

By making no further changes, Erasmus once more has two backs and six forwards on the bench.

South Africa: Willie le Roux, Sbu Nkosi, Lukhanyo Am, Damian de Allende, Makazole Mapimpi, Handre Pollard, Faf de Klerk; Tendai Mtawarira, Bongi Mbonambi, Frans Malherbe, Eben Etzebeth, Lood de Jager, Siya Kolisi, Pieter-Steph du Toit, Duane Vermeulen.

Replacements: Malcolm Marx, Steven Kitshoff, Vincent Koch, RG Snyman, Franco Mostert, Francois Louw, Herschel Jantjies, Frans Steyn.