The injury occurred after a tackle with Heskey, but Ferdinand says no fault can be laid at the England striker's door as it was a 'complete freak'.
"It was a complete freak, an accident," said Ferdinand of the incident with Heskey which caused the injury at England's Bafokeng Sports Centre base.
"The ball came in from one of the lads to Emile, I'd gone to try and tackle him from behind - he didn't actually see me coming - we both went off balance and Emile's weight went down on my knee.
"It's no fault of his at all. It's just a freak accident that could happen at any given time and it had no connection to any previous injuries I've had."