The Marvel Cinematic Universe (MCU) is all set for its third phase this year, releasing ten to 11 movies until 2019. However, a new installment of "Iron Man" is nowhere in sight.

Many "Iron Man" fans would hope to see "Iron Man 4" as part of MCU's Phase 3, but according to Marvel's press release, the fourth film is not included in the list. It also remains to be seen if the movie will make it to the list of 2020 Marvel movies or not at all.

According to Marvel, three untitled movies are slated to be released in May, July and November 2020. Could "Iron Man 4" be one of them?

No announcement has been given yet, but ScreenRant reported that actor Robert Downey Jr. was said to be in negotiation for the fourth installment back in 2014. Yet, until now "Iron Man 4" is still in the unconfirmed category.

With that said, speculations are rife that if a new "Iron Man" will indeed happen, Downey, Jr. won't be in it. There are rumors suggesting that the actor won't be reprising his role since he is demanding for a higher pay.

Assuming that a fourth movie would be included in 2020, the actor would be 55 that time and it would also be physically demanding to play Tony Stark. Downey, Jr. also hinted that he's getting tired of the franchise and might retire following "Avengers 2."

"How many follow-ups to a successful follow-up are actually fun?" he said in an interview with GQ back in 2013, in reference to the injury he sustained while filming for "Iron Man 3." His statement was easily picked up as a hint on his retirement, according to Screenrant.

Whether or not Downey Jr. will come back for another "Iron Man" movie is a subject of speculations, but he will surely be remembered as the ultimate Tony Stark of the Marvel Universe.

If Marvel Studios decides to drop him out of the project, fans can only hope that they'll find the right replacement who's compelling enough to be Stark.