Mandela intends to appear at opener
But World Cup chief Danny Jordaan told reporters the decision on whether Mandela will appear at Soccer City for South Africa's encounter with Mexico would be determined on the day.
"He intends to be there," Jordaan said. "Whether he comes for five minutes or the whole match is not our decision.
"As things stand now there is a very good chance that he will be with us because he wants to be there."
Speculation on whether Mandela, whose health has become increasingly fragile in recent years, would take part has been rife for some time with the general expectation that any appearance would be limited to greeting the crowd at the opening ceremony just before kick-off.
His grandson Mandla Mandela said his family would monitor the weather before a decision on whether he should take part. "We wouldn't want to risk his health for a soccer game," he said.
But he added the intention was for Mandela to make an appearance which would be highly symbolic for South Africans.
"We will come out with him for 10 to 15 minutes for him to greet the fans and then he will enjoy the rest of the proceedings from his home," he said.