South Africa wasted 11 points from missed kicks and have drafted experienced flyhalf Handre Pollard into their side for Sunday’s must-win Pool B clash with Tonga in Marseille, with one eye on the knockout rounds should they get there.
"We had four opportunities within one metre of their goal-line, which we butchered," Nienaber told reporters. "That, for me, is a much bigger issue (than kicking) that we have to sort out."
Pollard returns to the team for the first time since August 2022, but Nienaber insists they have performed well without him and criticism of the flyhalf options in his absence, Manie Libbok and Damian Willemse, is unfair.
"In those 13 months that Handre wasn’t available, there were 16 test matches and we won 75 percent of those. Only three of those matches were played at home.
"Of the four losses, two were against Ireland, who are the number one team in the world, one to New Zealand in Auckland and then France in Marseille, where we got a red card.
"Yes, we are not consistent off the tee, but the guys that stepped in, I don’t think they did a bad job."
Nienaber says he is realistic about what Pollard will offer this weekend following his long lay-off for a calf injury as the Boks seek a bonus-point win to put them in the driving seat for a quarter-final place, likely against France in Paris.
"He hasn’t played top-level rugby since the first week in May, which is 19 weeks ago. In saying that, he’s a quality rugby player and we all know that. He has won a World Cup and a British & Irish Lions series before.
"He understands what top international rugby is about, but I think we must stay realistic and give him time to settle in and get used to the pace of it."
South Africa made 12 changes to their starting XV for the Tonga game and reverted to a 5-3 split on the bench with Libbok set to replace Pollard in the second half.