Carroll is on loan at West Ham having struggled at Anfield after arriving from Newcastle for £35 million in January 2011.
The Former Toon No 9 has yet to find the net for the Hammers.
Ferguson can never resist a dig at the Scousers, and his comments about Benitez are sure to open an old wound between the pair of them.
The inexperienced Rodgers is on a learning curve with the old war horse.
Fergie believes that Liverpool should have waited until confirming the signing of then Fulham striker Clint Dempsey before letting Carroll join West Ham.
The United boss feels it was the inexperience of manager Rodgers that caused Liverpool to essentially lose one player.
Sir Alex Ferguson: “They were after Clint Dempsey, that didn’t work out, and they had done the deal for Carroll.
“Maybe it was something they did not expect.
“He’d played not a lot of games for Newcastle and had to deal with a £35m transfer to a club like Liverpool.
“He was young and it was quite a big jump for him for that kind of money.
"We’ve gambled on young players in the past, a couple of million, something like that.
“But when you get to that level of £35m, you need to do a bit more homework and see how he is in the second season, maybe.
“Now it’s up to the boy to improve himself. He’s a great header of the ball and very aggressive. He’ll be a handful on Wednesday.”
Source: Newcastle United Mad