Robert Downey Jr. has played Tony Stark, better known as Iron Man in three "Iron Man" movies already, plus he has played the same characters in two "Avengers" movies, most recently "Avengers: Age of Ultron."

He will be playing Stark again in "Captain America: Civil War," which will be shown next year, but given the actor's age (50), many have began to question just how long he can play the superhero, or until when he will be willing to portray the character.

Downey himself has hinted that his days as Iron Man are numbered, much to the dismay of his fans. When The Hollywood Reporter asked Marvel Cinematic Universe President Kevin Feige about this dilemma, he said that fans have nothing to fear since they have Downey, as well as other superhero actors locked up for "many, many years" to come.

"Thankfully, we have everybody...planned out for as far as any studio has movies planned. But one day, it will be a combination," he revealed. "It will be a combination of choosing which characters to continue on with and explore and which to bring in, as we're doing with 'Captain Marvel' and 'Black Panther.' And certainly to recast in some way or another - as we've already done in certain cases. Certainly many other franchises have reached that milestone before we have and done that with great success."

One of the newbies of MCU is Paul Rudd's Scott Lang, better known as Ant-Man; and in fact, the tiny superhero will be making a guest appearance in "Captain America: Civil War" alongside Downey's Iron Man and Chris Evan's Captain America.

They are slowly building up his character to be a part of the Avengers, which already includes Jeremy Renner as Hawkeye, Scarlet Johanssen as Black Widow, Mark Ruffalo as The Hulk, Anthony Mackie as Falcon, and Elizabeth Olsen as Scarlet Witch.

For the longest time, Rudd cannot imagine his character as part of the Avengers, but while they were filming "Captain America: Civil War," things finally began to sink in and he felt like a giddy young boy.

"When I went to the set of 'Civil War,' I was 10 years old. There's Captain America, there's Iron Man. And not only that, but I'm doing scenes with them, calling them by their names. That feeling of excitement, the surreal nature of it is the best, it was great. I really felt for the first time part of the Marvel Universe," he shared.