South Africa Nelson Mandela will briefly attend the FIFA World Cup opening ceremony at Johannesburg's Soccer City on Friday, his family said on Tuesday.

Mandela, who will be 92 on July 18, made a rare public appearance at an art exhibition at the Nelson Mandela Foundation in Johannesburg on Tuesday.

Interviewed by the South African Broadcasting Corporation at the exhibition, his grandson Mandla Mandela said the former South African President would greet "fans, friends and players" at the stadium for 10-15 minutes before being driven off.

Mandela, who spent 27 years in prison for anti-apartheid activities, became South Africa's first democratically elected president in 1994.

His presence invariably boosts sporting performance. This phenomenon is known in South Africa as "Madiba magic" in reference to his clan name.

Recently a Hollywood film, Invictus, was released, capturing Mandela's influence in the success of the South African national rugby team in winning the 1995 Rugby World Cup.

On Sunday South Africa President Jacob Zuma said he hoped Mandela would be at the opening.

"If he did not appear, we would understand. If he is there, it will be a bonus for this tournament. We wish he would be there," he said.