Arendse clumsily challenged the airborne Barrett and the contact caused the Kiwi to flip spectacularly and land on his head and neck.
The South African was shown a red card by Australian referee Angus Gardner before being stretchered off the Mbombela Stadium turf with a suspected concussion.
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The 26-year-old – playing his second Test as a replacement for injured superstar Cheslin Kolbe – had enjoyed an excellent game before that brain fade and scored the opening try of the 26-10 win to open the Rugby Championship.
Arendse pleaded guilty to what SANZAAR called a “reckless” and “highly dangerous” collision and will be sidelined until South Africa’s final game of the championship at home to Argentina.
Barrett was cleared of a serious neck injury but is in doubt for the re-match at Ellis Park on Sunday as the All Blacks attempt to snap a rare three-game losing streak.
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Under-siege New Zealand coach Ian Foster was afterwards seething at South Africa’s aerial bombardment.
“Massive concerns,” Foster said regarding the Arendse-Barrett incident, before the suspension was handed out.
“It’s probably the worst I’ve seen. It was pretty disappointing because it happened in the 10th minute as well (to All Blacks fullback Jordie Barrett) and they deemed it was fair.
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“Part of the problem in the game is in the lineout, if you throw a jumper over to their side with an arm up, it’s considered obstruction, whereas it’s becoming a free for all for jumpers just to be able to jump and stick a hand out and say they’re competing.
“It needs to be addressed.”
All Blacks halfback Aaron Smith admitted the tourists needed to deal better with the predictable but highly effective tactics.
“Our ability to defuse their bombs is something we need to fix,” Smith said.
“Their tactics there I think are a little bit borderline. To see Beaudy do a full flip is pretty scary. That’s a part of the game that needs to be looked at, but we’ve got to do a better job of protecting our jumpers because, as we saw, we would stop them on defence around their 30m line and they would just put a bomb up – and it works for them.”
Richie Mo’unga will replace Barrett in Johannesburg if he is ruled out.
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