With Costel Pantilimon starting in the game against Chelsea, the City manager has revealed that the Romanian goalkeeper will keep his place for the match against Wigan in May.
City's second-choice goalkeeper was chosen ahead of Hart in the semifinal win against Chelsea, as the Romanian conceded his first goal in the competition this season in the 2-1 victory.
Mancini, who celebrated reaching another FA Cup final as manager of the Manchester club, says he will stick with Pantilimon for the final against the Latics.
"Pantilimon is there to do what he did, Costel did very well but he's a very good keeper, it's what I expected," he told the club's official website.
"He will stay, we have four weeks to think about it but I think he will play [in the final]. He's worked very well behind Joe Hart and I think for Joe that's very important."
Samir Nasri and Sergio Aguero put City two goals in front in the clash at Wembley, before Demba Ba pulled a goal back for Chelsea.
Mancini won the FA Cup final with City against Stoke in 2011, and admits his priorities have changed towards the competition after slipping behind in the Premier League title race.
"We could be disappointed with the Premier League because I think we had another chance to win it if we had worked well last summer but we didn't, we made some mistakes probably," he said. "But now we are a good team, we go to the final and we have chance to get the second position and we have a chance to show we shouldn't be 15 points behind. I think this should be our target now."