The fourth installment of the "Iron Man" movie series is not a current priority for the Marvel Cinematic Universe. When the franchise does start working on the sequel, there is a possibility that Robert Downey Jr. will no longer be reprising his role as Iron Man.

According to Australia Network News, "Iron Man 4" was not included in the Marvel Cinematic Universe's Phase 3 of movies. Phase 3 began with the recently released "Doctor Strange" this 2016, and ends with another "Avengers" sequel that will be released in 2019.

This schedule only provides a fourth sequel to "Iron Man" to be released in 2020 or later. However, the Toronto Sun reports that Robert Downey Jr. may no longer portray Iron Man in an upcoming "Iron Man" sequel.

It is possible that Downey Jr. will be mentoring a younger actor to take over the Iron Man suit. In the current "Iron Man" comic series, Riri Williams — an African American teenager — has replaced Tony Stark and is called "Ironheart."

Another possibility is that Marvel may make a reboot of the "Iron Man" movie and cast a new character for its anticipated release in 2020. Marvel studios president Kevin Feige said in an interview with Postmedia Network (via Toronto Sun) that either alternatives are very much possible.

"These characters have been around for 50-plus years, and have been relatively ageless. Sometimes there are alternate stories where the character is younger than they usually are, or older, but they usually maintain a certain age. I think most of these characters that are iconic, like (James) Bond, like Batman, like Spider-Man, like Iron Man, someday will be portrayed by different actors," explained Feige.

In the meantime, Iron Man may not be having his own solo anytime soon but he will be appearing in the upcoming "Avengers: Infinity Wars" and "Spiderman: Homecoming" movies.

Aside from these appearances, Downey Jr. is currently preparing for a third sequel to another hit movie franchise, "Sherlock Holmes," Variety reports.