Described as one of the most exciting young prospects of recent years, Carr made history when he became the squad's first Muslim player on his maiden call-up in 2014, when he made his debut in a 22-6 win over Italy.
But a disastrous 2015 he blamed on a debilitating and mystery virus, as well as other issues, meant he dropped off the radar and notably missed possible selection for the 2015 World Cup.
The 25-year-old is now back “in-form” after coming off the bench in a 37-21 loss to England to earn a place in Allister Coetzee's starting XV against the Azzurri in Florence on Saturday.
After losing for the first time in a decade to England at Twickenham last week -- their fifth test reverse in six outings -- the wounded 'Boks are out for redemption.
And Carr, despite not playing at his preferred No 8, wants to show he fully deserves just his fourth cap.
“I was very emotional about falling out of the 'Bok squad in 2015. It was a big year because it was a World Cup year and as a result I really struggled mentally,” Carr said in Florence on Thursdady.
“I took it out on my family and they could see how much it was affecting me. I'm grateful and blessed to be here again and I'm hoping to make a difference.”
Carr said he had “seven to nine” doctors probing, in vain, the virus that compounded his nightmare year in 2015.
But he added: “The illness was when I fell back but I made a full recovery so I can't stand here and blame the virus for losing my place.
“It happened, it's in the past and I'm here now, starting against Italy. I've stepped up mentally and I'm the in-form Nizaam Carr that people know.
“I slowly picked up and there are thousands of kids who want to play for the 'Boks. I have a responsibility to not only play for my community, myself and my family, but for all South Africans to make them proud.”
Carr replaced Lood de Jager for the final 12 minutes at Twickenham, and did enough to impress Coetzee.
With lock Eben Etzebeth ruled out of the match due to concussion, Pieter-Steph du Toit will return to the second row after playing as flanker against England.
Carr will form a new back row with Willem Alberts moving to blindside after operating at openside last week and Warren Whiteley retaining his place at No 8.
“I've been blessed to be able to able to play No 8 and No 6, although I 100% prefer eighthman,” said Carr.
“I have to adapt my game because I can't be standing out wide and playing that linking game I do as a No 8.
“I need to be at the breakdown first because Italy will look to make those leg tackles and get the stealer in over the ball.”
Coetzee said: “They (Italy) do tackle around the legs and the first man is in hard, so we have to make sure we win that race to the ball this weekend.
“I think Nizaam will do well in that department in securing possession to build continuity for us.”
With wing Bryan Habana also returning after sitting out injured against England, South Africa have been given an extra morale boost.
But Carr said the 'Boks will have to focus if they are to get that spring in their step again.
“I fully believe that we as Boks can turn around what has been a tough season. I trust every single player, the coaches and the plan and it's just up to us as players to cut out the silly errors,” he said.
“We have been good in the first 20-30 minutes but then the concentration seems to go. So we have to stick to that for the whole game.”
Original source: Carr ready to relaunch Boks bid against Italy