Villa are just one place above the relegation zone ahead of today's match against the Red Devils.
Ferguson believes that Lambert needs time to get things right in the Midlands.
He told reporters: "Paul Lambert is a new manager there. It's a big task and a daunting one as Villa are not where everyone expects them to be.
"If you look at the team, it's a completely new team: a new back four, a new midfield and a new striker from the Belgian league [(hristian Benteke). It does take time to change teams.
"When you've got that many new players, it's hard but Paul has done well as a manager and is still young. Villa have a great history of course and I think it's probably correct to say they haven't matched their expectations over the years."
United have won seven of their last eight games ahead of the trip to Villa Park.