Agbonlahor will have a key part to play when Villa attempt to overturn a 3-1 first leg semi-final deficit in Tuesday night's Capital One Cup clash with visiting Bradford.
He is desperate to get back to Wembley to put behind him an incident against Manchester United three years ago after only five minutes of the final.
Agbonlahor was hauled down inside the box by Nemanja Vidic and, although referee Phil Dowd gave a penalty, the United defender escaped a red card despite what appeared a clear goalscoring opportunity.
It was a pivotal moment as United recovered from going behind to James Milner's spot-kick to win 2-1.
Agbonlahor was reluctant to talk about the incident ahead of the semi-final but said: "You want to make it right, what happened in that last final.
"It is a case of unfinished business, definitely.
"The same sort of thing also happened that season in the FA Cup semi-final as well against Chelsea.
"I should have a penalty against Mikel. That's what happens. Refs miss things sometimes, that's football.
"We've got to put that behind us now. We've just got to look at the Bradford game. We've got 90 minutes to get three goals to get through the tie."
Agbonlahor believes an early goal is key to Villa's chances of going through.
He said: "In the first leg the conditions, the pitch, the way they played, it suited them. We missed a lot of chances as well.
"If we can get that early goal like we did against West Brom at the weekend, everyone's confidence gets up.
"It is not going to be easy. Bradford will be dangerous on the counter-attack and we will respect them.
"But it should be a great atmosphere and the fans will play their part."