South Africa flanker Arno Botha has been ruled out for the rest of the year after rupturing ligaments in his left knee against Scotland on Saturday.
The rising star lasted just four minutes of his second Test, having made his debut against Italy the previous week.
He ruptured his collateral and anterior cruciate ligaments and will need an operation and a lengthy rehabilitation period.
"Losing Arno is a big blow as he had a very good Test debut last weekend against Italy," said Springboks coach Heyneke Meyer.
"Luckily he is still very young and I'm sure with the correct medical treatment and rehabilitation we will see him back on the field again in 2014."
Meyer said that a call on a possible replacement for Botha will be made at a later stage with the Springboks to face Samoa in their final four nations tournament match in Pretoria on Saturday.