"It was a tackle and then there was big pain," confirmed Capello. "He put his feet in the grass with Heskey and then he moved.
"The other players were upset. They stopped training.
"All the players who are here with me are important. But he is one of the starting players, the captain, a leader."
Scan results were assessed by two different members of the England medical team, but agreement was instant; Ferdinand has been ruled out for up to six weeks, which offered no opportunity for recovery in time to play any part in South Africa.
"It couldn't have been much worse on my first day," Capello admitted. "It is obviously bad news and everyone with the squad is very disappointed and sorry for Rio.
"It was an accidental injury in training, but had nothing to do with the pitch.
"It is the curse of the captain."