Ferdinand appeared to barge the Spain international to the ground before helping him to his feet in an off-the-ball collision which went unseen by referee Howard Webb.
However, a spokesman for the FA told Press Association Sport that Ferdinand would not face retrospective action.
The confirmation means Ferdinand will be free to play in the quarter-final replay after the teams drew 2-2 at Old Trafford on Sunday.
Goals from Javier Hernandez and Wayne Rooney inside the first 11 minutes put United apparently on the brink of a semi-final berth.
But the Blues hit back in the second half and Eden Hazard halved the deficit just before the hour, with Ramires levelling in the 68th minute.
The winners will face Manchester City in the last four but a suitable date to hold the replay has yet to be settled on.
Source: PA
Source: PA