Ferguson had hoped that Vidic would begin his comeback against Cluj in Manchester United's final Champions League qualifier tonight and help stiffen his defence for the weekend.
"I do not think he will play,'' said Ferguson. "He feels he needs another few days' training. He will not play in the derby if he doesn't play against Cluj, although I wasn't considering him for Sunday anyway.''
Ferguson compared recent mishaps to cartoon-like defending.
"We are getting punished for every ball that goes into our box at the moment but we should be defending far better," said Ferguson.
"We expect to do better. If we perform like that on Sunday, God knows what is going to happen to us."