For several months, there have been talks about another Iron Man movie, despite it not being included in the lineup of Marvel Cinematic Universe movies scheduled for the years to come.

Robert Downey Jr. was also the subject of rumors at it had been debated whether or not he would be appearing in another "Iron Man" movie dubbed as "Iron Man 4."

This debate went on for so long, until recently, when the actor himself confirmed that there won't be another Tony Stark movie.

In an interview with USA Today last month, the 51-year-old actor confirmed that "Iron Man 4" is not in the cards. This is not the first time that the actor revealed the fate of the movie.

Still, fans refuse to believe that he won't be appearing in another "Iron Man" standalone film. Some reports indicate that there is a possibility for the movie to be released, considering Marvel has plans for three untitled movies, which are slated for a 2020 showing.

With Downey Jr. confirming several times that he won't be in an "Iron Man" standalone film, speculations are rife that another actor might step in to take the iconic role of billionaire Tony Stark.

If there is indeed a fourth "Iron Man" movie for 2020, Downey Jr. will be 55 years old by then and many doubt that he would still be interested in the role. In addition, it could be that a fresher, younger actor might replace him, but will fans be ready to accept that?

According to Joe Russo, co-director of "Captain America: Civil War," it would be hard to replace an actor as remarkably talented as Downey Jr. since many agree that the character Tony Stark is made for him.

"It's almost impossible to replace Robert, he's the biggest movie star in the world. One close up from Robert is worth another actor's entire performance, he's incredibly gifted and insanely talented," Russo told Forbes.

Fans won't have to miss Downey Jr. or Tony Stark that much because the actor and his famous character will be featured in the upcoming "Civil War" movie that's showing on May 6 in the U.S. He will also be in the two-part film, "Avengers: Infinity War."