South Africa's quarter-final preparations have been hit by a new race row just a day before they face New Zealand in Melbourne.
Willemse is the only black player in South Africa's top 22
South African Rugby Union chief Mvuleli Ncula warned on Friday there were not enough black players in the current side.
Wing Ashwin Willemse is the only black player in the 22-man squad.
And Ncula told the Pretoria News: "Everyone in South Africa rugby must take the blame.
"At the 1995 World Cup we had only one black player (Chester Williams) on the field and it was the same in 1999 when there was never more than one black player in the team (Breyton Paulse or Deon Kayser).
"Now we have only one black player in the match 22; if Willemse gets injured, we have an all-white team."
Following the collapse of apartheid, South African officials invested £9m to help black youngsters develop into future international players.
But Ncula is concerned the rewards have not been reaped.
The rugby chief's concerns come in the wake of racist allegations from the South African team camp against lock Geo Cronje.
Prior to the tournament, Cronje was kicked out of the Springbok squad after allegedly refusing to share a room or bathroom with black team-mate Quinton Davids.
He was subsequently cleared of racism by an internal inquiry but left out of South Africa's 30-man World Cup squad.
Then the team's media officer, Mark Keohane, resigned and exposed new claims of prejudice in the squad.
An independent investigation has since been launched into his allegations.