Earlier this week, former Blues midfielder Patrick Vieira said the decision to bring Paul Scholes out of retirement smacked of desperation.
Ferguson said: "Desperation? Paul Scholes is the best midfielder for the last 20 years."
United have won nine Premier League games and drawn one with Scholes in the team, suggesting the move has worked. It certainly has provided Ferguson with the opportunity to hit back in a week when Carlos Tevez made his controversial return to the Manchester City fold.
He continued: "(City manager) Roberto Mancini had a little dig at us a couple of weeks back. We are all going to play our hand. I have plenty of ammunition that way. Desperation? On Wednesday they played a player who refused to go on the pitch and the manager had said would never play for them again. What is that?"
Meanwhile, United legend Bryan Robson believes Ferguson's handling of Wayne Rooney's infamous night out last December could turn out to be the inspiration behind another Premier League title.
Ferguson has never explained why Rooney missed the New Year's Eve encounter with Blackburn. Rooney was at Old Trafford to watch United suffer a shock 3-2 defeat and it is thought he was not involved as a punishment for reporting for training earlier that week clearly unfit for work, a legacy of a night out with Darron Gibson and Jonny Evans.
Speaking ahead of the Soccerex European Forum in Manchester next week, Robson said: "The boss isn't interested in one individual. He is interested in the whole group. Not just his first-team squad but all the kids in the youth team and the reserve boys. It was a statement to say he would not stand for that type of behaviour. "
He continued: "He will always clamp down on something like that. When you look at certain managers, you ask whether they would have left Rooney out. They had a million injuries in that game. He is fielding a depleted team anyway and then he says 'I am not having him' and Wayne is left out.
"A lot of managers might have fined him but put him in because it was an important game and they didn't want to slip up. The boss saw the bigger picture."
Source: PA
Source: PA