South Africa's World Cup title defence suffered a major blow on Thursday when hooker Malcolm Marx was ruled out of the remainder of the tournament with a long-term knee injury as coach Jacques Nienaber delayed naming a replacement in the squad.
Nienaber believes he has enough cover at hooker, despite Bongi Mbonambi being the only remaining specialist number two, opening the possibility of a recall for flyhalf Handre Pollard or centre Lukhanyo Am.
The pair were not deemed fit enough when the World Cup squad was announced on August 8 but both played a major role in the team's 2019 triumph.
Pollard, whose accuracy off the kicking tee has been missed, has been in training with his English club Leicester Tigers in recent weeks.
"We'll assess our needs for the rest of the tournament and confirm who we are calling up as an additional player later this week," Nienaber said in a statement from South African Rugby.
Stormers hooker Joseph Dweba was the nominated standby option when the squad was announced.
Marx, who was not included in the matchday squad to face Romania in Bordeaux on Sunday, went down at training on Wednesday after having his knee caught in contact.
Scans revealed the extent of the injury.
One of the leading hookers in world rugby, Marx has also been a strong ball carrier for the Springboks and a key source of turnovers at the breakdown.
"First and foremost, we are extremely disappointed for Malcolm, and we wish him all the best in his recovery," Nienaber said.
"We have enough cover at hooker with Bongi and Deon in the squad, while Marco has also been training there and has been named on all our team sheets so far as a hooker option."
Mbonambi was selected to start against Romania with Fourie his replacement on the bench. Van Staden will start among the loose forwards.