Although Marvel fans are eager to see Robert Downey Jr. play the popular Iron Man in a solo film, a fourth sequel may no longer be possible. Chris Evans, who portrays Captain America, confirms his retirement from the superhero character and reveals Downey Jr.'s exit as well.

Fans of Downey Jr. playing Tony Stark on the big screen are eager to see a fourth film in the "Iron Man" series. However, there has been no announcements whether there will be a continuation of Tony Stark's solo story.

Although there have been no official announcements yet, Evans, who recently appeared on "The Ellen Show," confirmed that Downey Jr. may no longer reprise his role of Iron Man.

Evans initially talked about his retirement from the character of Captain America. However, before he hangs up his costume and shield, Evans confirmed that he will still be appearing in the upcoming "Avengers" film in 2018 and 2019.

However, in terms of Downey Jr. appearing in those two films, Evans expressed concern.

"Downey is far closer to reaching that point where he may walk away. And I don't know how you replace Downey as Tony Stark. I don't know who else can touch that," Evans revealed.

This causes fans to theorize how Iron Man will exit the film. Because Iron Man is an integral member of the Avengers, one speculation is that he will die in the upcoming "Avengers: Infinity War."

In an interview with Collider, Marvel president Kevin Feige did say that after "Infinity War," things will be very different.

"Certainly as we get to 'Infinity War' there is a sense of a climax if not a conclusion to, by the time we're at untitled 'Avengers 4,' the 22 movies that will have encompassed the first three phases of the MCU. And what happens after that will be very different," Feige explained.

There is no confirmation yet for a fourth installment to the "Iron Man" franchise.