Prop Ofa Tuuangafasi became just the fifth All Blacks player to be sent off in a test on Saturday when he was given a red card for a high tackle on Wallabies winger Tom Wright in the 24-22 loss to Australia in Brisbane.
"We just have to be better," Coles told reporters on a conference call on Monday.
"We do a lot of tackling practice in the week. We just have to lower our sights and targets to not get those red cards again.
"I suppose it's one on the chin for us."
Coles said at last year's World Cup in Japan, after an edict from governing body World Rugby for referees to be stricter on the high tackle to protect players, teams worked on lowering their centre of gravity.
"We did a lot of work to lower our height," Coles said. "We just have to make sure we get under the ball."
After four successive matches against the Wallabies, Coles and centre Anton Lienert-Brown said they were looking forward to the different challenge of facing the Pumas this week in Sydney.
Argentina have been in Australia for more than a month, but only managed to get their entire squad together last week after 13 European-based players who arrived late completed their mandatory isolation period.
They have played two matches against what has been essentially an Australia 'A' side and Lienert-Brown said he suspected the weeks of training together would mean they would be well prepared to face the All Blacks.
"I have no doubt they will turn up ready to go," he said.
"They are looking sharp. We expect them to turn up like the Pumas do normally."