The appearance of Iron Man on "Captain America: Civil War" has drawn more interest for a fourth standalone "Iron Man" movie sequel. However, "Iron Man" was not mentioned during the recently held San Diego Comic-Con and speculations on the movie and its release date began making the rounds.

"Iron Man" is said to have revived the career of actor Robert Downey, Jr. in the same way that the actor made the character famous. After three successful installments, the clamor for a fourth sequel continues.

During the earlier promotion of the movie "Captain America: Civil War," Downey has insinuated that the movie will also serve as "Iron Man 4," but in an interview with ABC News, he said, "I feel like I could do one more."

Many fans took it as a hint that Marvel could have decided to make a follow-up. However, during the Comic-Con, only the following movies were discussed: "Thor: Ragnarok," "Dr. Strange," "Black Panther," "Spiderman: Homecoming," and "Guardians of the Galaxy Vol. 2."

Marvel has a lineup of movies coming up until 2019, and while some believe "Iron Man 4" will be considered for 2020, Downey's age has given rise to many speculations that he may not be able to play the character anymore.

Marvel illustrator Alex Maleev further fired speculations when he posted a different Iron Man concept on his Twitter account. The image looks like a cross between Iron Man and Doom, which led to suggestions that it could be named Iron Doom.

Time also got to interview "Iron Man" writer Brian Michael Bendis who created Riri Williams, a female "Iron Man" who was recently introduced. The events take place after "Civil War II," when Tony Stark is going through a tough time. He becomes aware of the student who successfully reverse-engineered one of his old armor suits.

Could "Iron Man 4" see Downey guiding an apprentice? For now, viewers just have to wait for further developments.