Handré Pollard may miss South Africa's final game of the Rugby Championship as he struggles to recover from a possible concussion.
The 21-year-old took a knock to the head during the Springboks' home defeat to New Zealand although he passed the head injury assessment on the day.
However two days later he began to show symptoms of concussion, and he will need to pass a test at the end of the week before being cleared to play.
"Handre passed the head injury assessment during the game and immediately after, but then two days later there were signs of what we called delayed concussion," explained Springbok doctor Craig Roberts.
"So we will only know later in the week, after further tests are carried out, whether he will be available for selection."
Having lost their first two games of the competition, South Africa cannot now win the Rugby Championship, and Pollard may well be preserved with Pat Lambie and Morné Steyn both waiting in the wings.