Although the Old Trafford boss had pledged to continue with his policy of playing his youngsters in the competition, but United's disastrous FA Cup exit against League One Leeds has forced the Scot to rethink his plans for the trip to Eastlands.
The Sun quoted a furious Ferguson as saying: "I didn't expect that. The preparation was very good but I was shocked at the performance. It's a disappointment. Human beings can always surprise you, but we didn't expect that today.
"We have a semi-final on Wednesday and a lot of these players today won't be playing. I had the team in mind but there may be one or two changes now. We need to get it out of our system. You must get over these kind of results quickly," he added.
Fergie claimed only second-half sub Antonio Valencia had come out with any credit from the 14 players who featured for United.
"I don't think any of ours can say they had a good day. Only Valencia can say he had a fair performance when we got the ball to him - but it took us about 10 minutes to do that," he said.
"Leeds had a bigger appetite than us for most of the game. You need a bit of luck in games like this and they got it. But they deserved it because they played really well."
"It was a bad goal for us to lose but the whole performance from us was bad in the first half. We never got going and the quality of passing was bad.
"You always expect us to get a goal at Old Trafford and the intensity of our game improved a little bit in the second half," he added.