The pair were sent home after breaking a curfew and made an emotional departure from the team's headquarters. In a brief statement, Augustine said he apologised to his team-mates for "for having let them down at such a crucial stage in the World Cup by breaking team curfew this weekend in Vichy."
At the same time, squad officials disclosed that there had been two previous incidents in Vichy, where players broke curfews set by the coach, Philippe Troussier. A group of 15 was involved in the first incident and five in the second, two days later. They will all face fines.
A tearful Augustine and a contrite Mokoena refused to speak to journalists as they left the team hotel by car for Paris, but Augustine released his statement later.
"Although there were a number of factors that led to me breaking my curfew, my behaviour was unprofessional and unnecessary," he said.
No details of the "factors" were given, but Augustine was understood to have been unhappy with his substitution by Troussier at half-time in South Africa's 1-1 draw with Denmark in Toulouse last Thursday.
"I sincerely regret my actions and hope to have the opportunity to represent my country in the future," said the Austrian-based player, who has 29 international caps.
"The decision will not affect us for the match," said the goalkeeper, Hans Vonk. "What it does more is to affect the image of South Africa."
Both Augustine, 26, and Mokoena, 23, were suspended by South African Football Association officials after a meeting on Sunday. They were expected to board a flight to Johannesburg last night.
The South Africans say they expect no favours from France as they try to overtake Denmark for the runners-up spot in Group C tomorrow.
South Africa need to beat Saudi Arabia handsomely in their final group match in Bordeaux and hope the French hosts do the same against Denmark in Lyon to have a chance of going through to the second round.
John Moshoeu, who will win his 49th cap if he keeps his place in midfield, said South Africa should not be distracted by the French game against Denmark. "We mustn't look to depend on them," he said. "We must win our game and try to score as many as we can. We can't budget on just a few goals and hope that the French hammer Denmark.
"We have to go out and do it ourselves. But Saudi Arabia cannot be taken for granted and will be no walkover."
The defender Pierre Issa said he believed a new-look French team, without the suspended playmaker Zinedine Zidane, would beat Denmark.
"The players who have been on the bench and will now get a chance will play as best they can to assure they stay in the team," he said. "That's good for South Africa but we have decided in the team to just concentrate on our own game and worry about the Denmark result after the game."
Vonk said the South African team were focused on the match. "We've had some trouble but the players are professional and know what awaits them if they win," he said. "We can achieve a place in the next round."
South Africa leave Vichy for Bordeaux today and are expected to make just one change in the team that drew with Denmark. The left-winger Delron Buckley is expected to take the place of Augustine.
Sacking the coach, Carlos Alberto Parreira, has eased the pressure on the Saudi Arabian team and boosted morale, the president of their World Cup delegation has said.
Prince Walid Ben Bader Ben Saoud said he expected the team to improve against South Africa on Wednesday. "The team are in good spirits. We have noticed a real change in their state of mind," he said.
Parreira was sacked on Saturday after his side lost 4-0 to France. They had lost their opening game 1-0 to Denmark. Mohammad Al-Kharashi has been named caretaker coach.