John Williams, the first post-isolation Springboks coach in 1992, died on Thursday aged 78, his former franchise the Bulls announced.
Bulls president Willem Strauss told the South African media that Williams died in a Pretoria hospital after being in a coma for 10 days.
Williams, who played 13 times for the Springboks as a lock, struggled as national coach during one season in charge, winning one of five Tests before being replaced by Ian McIntosh.
He was elevated to Springboks coach after having a similar role with the Bulls, who won numerous trophies when he was in charge.
"John Williams was one of only six people who played for South Africa and then also coached the Springboks after unity in 1992," said South Africa Rugby president Mark Alexander.
The others were Carel du Plessis, Nick Mallett, Rudolf Straeuli, Allister Coetzee and current head coach Rassie Erasmus.
"He was a tough-as-nails lock and a great lineout jumper, and (had a great) knowledge of the game," added Alexander.
"John had a successful career in coaching, although the return to the Test arena in 1992 was a difficult time for the Springboks.
"The Bulls teams from the late 1980s carried the hallmark of his coaching and were almost unstoppable as they dominated local rugby for a number of years.
"As a true rugby man, John ploughed back into the game after he had hung up his boots and he remained a loyal supporter of the Bulls and the Springboks."
South Africa were barred from the first two editions of the Rugby World Cup, in 1987 and 1991, because of apartheid.
They were readmitted to international rugby in 1992, two years before the first multiracial elections ushered the Nelson Mandela-led African National Congress (ANC) into power.
AFP