South Africa captain Siya Kolisi suffered a facial injury in a Rugby Championship victory over New Zealand, which could rule him out of a rematch in Cape Town on Saturday.
After a dramatic comeback, the Springboks edged the All Blacks 31-27 in Johannesburg on Saturday, giving them a third consecutive victory over their greatest rivals.
Catch every Rugby Championship match live, ad-free and on demand on Stan Sport
The victory in a thriller watched by a capacity 62,000 crowd came at a price with flanker Kolisi and winger Kurt-Lee Arendse likely to miss the fourth-round game.
"It might be a fracture and, by the looks of it, might be the cheekbone. The doctor will have to take a look," Erasmus told reporters.
Double World Cup winner Kolisi was replaced after 61 minutes with suspected concussion, but passed a head injury assessment (HIA).
Arendse, also benched in the second half, failed a HIA and is unlikely to play in Cape Town.
Erasmus hailed his players after a win that gave South Africa an eight-point lead over second-placed New Zealand halfway through the six-round southern hemisphere competition.
Argentina are third, one point behind New Zealand, despite a 20-19 home loss to Australia in La Plata.
"It wasn't me, it was the players," said the coaching mastermind behind the 2019 and 2023 Rugby World Cup triumphs.
"It was the guys making plans. It was them seeing that we are under the pump. It really wasn't the coaches at half-time, it was the players."
A point behind at half-time, South Africa trailed 27-17 with 12 minutes remaining before tries from replacements Kwagga Smith and Grant Williams snatched victory.
Erasmus praised full-back Aphelele Fassi and 22-year-old fly-half Sacha Feinberg-Mngomezulu after the rematch of the 2023 World Cup final, won 12-11 by the Springboks in Paris.
"Fassi was fantastic. Willie (le Roux) helped him during the week, while Handre (Pollard) assisted Sacha. There are many examples like that of older players helping younger Springboks.
"It is inevitable that we will lose some matches, but as long as we keep showing incredible character against a team like New Zealand, I will be happy."
