David Moyes' side have suffered Premier League defeats against Everton and Newcastle and it could be the first time they have lost three successive league games in 12 years if Villa beat them.
However, the last time the West Midlands side won a game anywhere against United was 1-0 at Old Trafford four years ago, when Agbonlahor scored the winning goal.
Paul Lambert's men can go level on points with ninth-placed United with victory on Sunday and 27-year-old Birmingham-born Agbonlahor insists they have the confidence to cause a major surprise.
"We know they can be beaten, but we also know it will be a tough game," he told the Daily Express.
"What I remember of the goal is that Ashley Young sent over a good cross and I headed it near post, past the keeper. I think that was the first time Villa had won at Old Trafford for more than 25 years.
"We came close to beating them last season at Villa when we went 2-0 up and played well. United have been in those situations many times, however, and they came back strongly and we couldn't hang on, losing 3-2.
"But we feel that we're progressing all the time, the players have learned from those kinds of experiences.
"The manager is always the same in the way we approach games. We're always trying to win it, so it will be the same approach against United."