Fly-half Cooper, who is missing from the squad because of knee trouble, made his outspoken comments at the weekend but his team mate responded on Monday by saying there was a convivial mood in the dressing room.
"This won't be a distraction for us," Ashley-Cooper told a news conference in Johannesburg. "There's a great buzz in the squad and we're excited to be here.
"We've had two good wins in this competition and we feel we're building as a group."
Cooper had launched a Twitter outburst against Robbie Deans, venting his frustration at the tactics of the coach of the Wallabies and also at the Australian Rugby Union.
The 24-year-old fly-half, who needs a knee operation and could miss the tour of Europe in November and December, then continued his tirade in an interview with the Australian Associated Press.
"There are a lot of people who are afraid to say what they feel so they just go along with it and nothing is going to change," Cooper told the news agency.
"That's why I feel so strongly. I don't want to be involved in the toxic environment and that's how it is at the moment."
Cooper's original Twitter comments had infuriated Jim Carmichael, chief executive at his club side the Queensland Reds.
Carmichael said he would meet the player and warn him about his outburst.
"I'm fed up," the Reds boss told the local Courier Mail newspaper. "Quade is making silly comments that do damage to our code."
Cooper's tirade against Deans came after the coach had criticised an error-prone display by the New Zealand-born playmaker following his return from previous knee surgery.
The fly-half also announced that he would like to join All Black Sonny Williams in the National Rugby League.
While Australia have won their last two tests against South Africa and Argentina, Deans is still under pressure at home because of his record of two wins in 16 matches against the All Blacks.
South Africa coach Heyneke Meyer is also feeling the heat with his team having picked up just one victory in four Rugby Championship matches.
"The Springboks are facing similar challenges to us with a lot of injuries and having to give opportunities to younger players," Ashley-Cooper said on Monday.
"They are coming off two disappointing losses so they'll be pretty motivated and we expect it to be really tough to win in Pretoria on Saturday."
Ashley-Cooper, 28, a veteran of 71 Tests, said Loftus Versfeld would not be a place for the faint hearted.
"Playing there is always pretty tough, you're usually up against quality opposition and a hostile crowd that they feed off," he added.
"Plus the altitude and the pace of the game there means it's always a challenge. A win is something we've never achieved before in Pretoria ... so there's a lot of motivation for us."
Australia are to name their team on Thursday while South Africa will unveil their line-up 24 hours earlier.