SOUTH Africa dangerman Cheslin Kolbe has been ruled out of the World Cup semi-final against Wales.

The livewire Toulouse winger has been struggling with an ankle injury since the win against Italy in the group stages and was forced off at the end of the quarter-final win against Japan.

The 23-year-old, who was compared to Jason Robinson by Wales defence coach Shaun Edwards earlier this week, has been replaced by Sharks speedster Sbu Nkosi.

His inclusion is the sole change to the 23 that overpowered the hosts in Tokyo last weekend.

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

"We've been fortunate to have been able to be pretty consistent in selection and we've built some nice momentum, but the challenge just got a lot tougher on Sunday.

"Wales are the reigning Six Nations champions - as well as Grand Slam winners - and apart from three defeats in their Rugby World Cup warm-ups have put together a really good sequence of results.

"But we've also found some rhythm and we'll be ready for the challenge."