Lions prop JC Janse van Rensburg will fly to London on Tuesday evening to replace the injured CJ van der Linde in the Springbok squad.
Van der Linde will return home to South Africa. He picked up a hamstring injury at training on Monday.
"Seeing that Gurthrö Steenkamp was also not feeling 100% on Monday and after the late withdrawal of Tendai Mtawarira ahead of the Ireland Test, we've decided it would be best to have proper cover at loosehead," said Springbok coach Heyneke Meyer.
"JC is an experienced player at Super Rugby and Currie Cup level and also captained the Golden Lions very well this year.
"He's been knocking on the national door for long and this will provide an opportunity for JC to experience the Springbok culture and structures."