Nogwanya sustained the injury in Banyana’s 1-0 defeat on Wednesday to Sweden where she played only 40 minutes of the first half – in her first Olympic Games – before she was substituted for Linda Motlhalo.
The player has been advised to rest by the medical team after she underwent scans.
Nogwanya’s withdrawal from the squad means coach Vera Pauw will be forced to make changes to her starting line-up when they face China on Saturday, at the Olympic Stadium in Rio de Janeiro.
Banyana will have their final training session on Friday, ahead of their encounter with China who lost 3-0 to Brazil in their first game.
Banyana goalkeeper Roxanne Barker believes this is a match they have to win to stay in contention for the next round.
“We did really well against Sweden but we were gutted to concede that goal. The only positive is that the performance on that day will surely give us the needed boost to face China with a lot more confidence. I think what we did against Sweden has made people now realise that South African Women’s football is on the rise and that’s thanks to all the good preparation we had over the last few months,” said Barker.
“We know our capabilities, we know our strengths and we showed that we can mix it up with the best. While all the matches are very important, the upcoming one with China becomes even more important as we did not get any points in our opener. We know we deserved something from that match, but it is now behind us and we have to look forward with renewed energy to our next assignment to make sure we get positive results so that we stay in contention for the quarterfinals. All is not lost, but we have to work extra hard to win because a loss is unthinkable. Also we don’t want to go to our final match against Brazil needing points desperately.”
The Banyana clash with China kicks off at 7pm local time (midnight SA time).
The last group stage match is the much-anticipated clash with hosts Brazil on Tuesday, August 9 which will be played in Manaus, Brazil.