South Africa first five-eighth Pat Lambie will not be available for the third Test against Ireland in Port Elizabeth due to concussion, the South African Rugby Union (SARU) said.
Lambie was knocked out by a high tackle early in the first Test when Ireland beat the Springboks 26-20 in Cape Town, ruling him out of Saturday's second match at Ellis Park which South Africa won 32-26.
"Pat is still experiencing symptoms of concussion and because of that we cannot start the Return to Play Protocol," SARU said in a statement.
Three other South African players will undergo scans on Monday. Loose forwards Duane Vermeulen (elbow) and Warren Whiteley (shoulder) and prop Trevor Nyakane (ankle) are doubtful for the deciding Test in the series.
Lock Lood de Jager, ruled out of the second Test because of a calf injury, is still undergoing physiotherapy.
Captain Rory Best feels Ireland can still clinch a historic series triumph in South Africa with the right mental attitude in the third and final Test, despite letting a second successive victory slip from their hands at the weekend.
Ireland, who won in South Africa for the first time in the opening test in Cape Town, led the Springboks by 16 points with 20 minutes to go in Saturday's second Test before being overwhelmed by a rousing comeback by the home side.
"Obviously it was incredibly disappointing and frustrating but we know now it's 1-1 and we still have a chance to win a Test series over here," said Best as he and his teammates headed to Port Elizabeth.
"I think probably the most important thing over the next days is to take this loss on the chin. Sometimes you need to just let these losses dwell in you a little bit and then come out the other side stronger.
Ireland were 19-3 up at halftime and in command against a Bok team jeered off at the interval by their own supporters. The tourists led 26-10 with around 20 minutes to go before a resurgent
South Africa steamrollered a tiring opponent to win.
"If we get ourselves in that position again in the next Test then we have to make sure we don't make the same errors we did this weekend," said Best after winning his 96th cap for Ireland.
"It will take a big investment from us but we came here to win a Test series and we are still in with a shout of doing that."
The last-gasp defeat would make Ireland better as a team and individuals would learn from the experience, he said.
"So we'll hurt for a little bit, dust ourselves down and take a big stride forward to try and improve," Best said.
Reuters