Well before the movie's release, it was revealed that Anthony Mackie's Falcon character would cameo in Marvel's 'Ant-Man' film by a very brief TV spot.

While there weren't any trailers or footage that spoiled why the character was included within the film, Marvel Studio's President Kevin Feige spoke on it in an interview with Fandango. He begins with explaining how the idea came about:

"That came about in a really natural way, and it was actually the idea of Paul Rudd and Adam McKay. Peyton Reed had pointed out that in heist films, there's usually a preheist. There's usually a little adventure mission the characters need to go on before the primary heist - to get a tool, or get a device."

The scene served to introduce an tease the new Avengers facility that was shown at the end of 'Age of Ultron.'

"I said that would be cool, and not only that but I also told them we were introducing a whole new Avengers facility at the end of Age of Ultron," Feige continues. "So not only could they encounter the Falcon, but it would make sense if he had to go to what he believed was an old Stark facility and was unaware it had now become a major Avengers facility. It sort of naturally spiraled like that."

Feige clarifies that the Falcon's inclusion in the film was completely intentional and wasn't a replacement for any other character. He also went on to point out a few key easter eggs.

"If you were to freeze the frame when Ant-Man is flying over the Avengers facility, there are new landmarks and buildings in that frame that you won't see until Captain America: Civil War..."

'Ant-Man' is currently airing in theaters.