Aug 3 (Reuters) - South Africa are sweating on the fitness of flyhalf Handre Pollard ahead of their final Rugby Championship test against Argentina at King's Park on Saturday.
The 21-year-old, who was impressive in defeats to Australia and New Zealand in this year's competition, took a blow to the head against the latter in Johannesburg nine days ago.
He was cleared to carry on playing in the game, but two days later was diagnosed with delayed concussion and will be assessed again later in the week.
"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," team doctor Craig Roberts told reporters in Durban.
"So we will only know later in the week, after further tests are carried out, whether he will be available for selection."
Should he be ruled out or rested, one of Pat Lambie or Morne Steyn will make a return to the starting lineup.
Better news for the Springboks was that the experienced trio of centre Jean de Villiers, scrumhalf Fourie de Preez and flank Willem Alberts all made it through a training session unscathed on Monday as they aim to make a return to the side having not yet featured in 2015.
"Jean is a player who took a back seat a bit so that he could get some game time, and the news is good on that front as he looked good in training and should be available for selection for this week's game," Roberts said.
"It was also a good workout for Fourie du Preez. We will obviously monitor how he responds to the training, as we will with Jean, before making a final decision.
"Willem is also looking good. We've been building him up for a while now, and if gets through the training week then he will be ready to play."
Two more players back in training on Monday were centre Jan Serfontein and prop Steven Kitshoff.
The World Cup takes place from Sept. 18 to Oct. 31, where South Africa have been drawn in Pool B, alongside Japan, Samoa, Scotland and the United States.