The England international has come under criticism for recent performances but up until now he had been defended by his club.
Following the 2-0 loss to Liverpool, Ferguson has come out and said that Ferdinand has to find form soon.
"He has to get good form,” Ferguson said.
"That's an important issue for the coach to pick the right team. In defence you've maybe got more options than other positions.
"He'll need to get his form right."
Despite these comments, Ferdinand is remaining calm as he continues to recover from several niggling injuries.
"I'm not interested in proving anyone wrong,” the defender said.
"I'm not interested in what people say about me. I'm just trying to get games under my belt."