A new Avengers: Doomsday theory provides a possible explanation for how Robert Downey Jr.’s casting as Doctor Doom could work out in the Marvel Cinematic Universe, and it would be all Captain America’s fault. RDJ started the MCU in 2008 with Iron Man. As the years pᴀssed, Chris Evans joined Downey in a league of their own, becoming the two faces of the MCU as Captain America and Iron Man. Together, they led some of the best movies in the MCU and even seemed to leave the franchise at the same time with 2019’s Avengers: Endgame.

However, as the MCU’s Multiverse Saga gets ready to enter its final years, Marvel has brought back its biggest stars. Chris Evans played a version of the Fantastic Four’s Johnny Storm in ᴅᴇᴀᴅpool & Wolverine, with the actor now set to star in at least one major movie on the MCU’s schedule, Avengers: Doomsday. Downey will also be back for the project, but he will be playing Doctor Doom instead of Iron Man. With many questions emerging after the casting was announced, Evans’ possible return as Captain America could explain Downey’s surprising role in Avengers: Doomsday‘s story.

Marvel Studios Has Reportedly Tried To Tell A New Chris Evans Captain America Story Before

The MCU Can Now Make That Story Happen

When Chris Evans was reported to have joined the cast of Avengers: Doomsday, his character and how big of a role he had in the movie were not specified. However, another piece of casting information suggests Evans is back as Captain America or at least Steve Rogers. According to ᴅᴇᴀᴅline, Evans is likely playing Rogers in the MCU movie. Adding to that, Hayley Atwell will reprise her role as Agent Carter in Avengers: Doomsday. As the characters were last seen together in Avengers: Endgame, that has led to speculation about Marvel’s plans for the duo.

The Avengers: Doomsday casting report also revealed a surprising update about a lost MCU movie. Back in 2021, it was reported that Evans had talks with Marvel to return as Captain America. However, the actor denied the claim, and nothing seemed to come from it. Now, ᴅᴇᴀᴅline has reported that the studio had plans for a standalone movie featuring Evans’ Steve Rogers and Hayley Atwell’s Peggy Carter. According to the report, Marvel could not nail down a story for the film, with rumors suggesting it could have been about Captain America’s quest to return the Infinity Stones.

Avengers: Doomsday Theory Reveals How Captain America Might Be Behind RDJ’s Doctor Doom

Marvel Can Use Its Past Plans For Steve Rogers

The report mentioned that as Marvel could not settle on a story for the project led by Evans and Atwell, the studio decided to bring the stars back into the fold for Avengers: Doomsday. A theory for the next Avengers movie was shared on Reddit by user LollipopChainsawZz, and it shows how Chris Evans’ possible return as Captain America could reveal that Steve Rogers is to blame for Robert Downey Jr.’s Doctor Doom. According to the theory, the events of Avengers: Doomsday are caused by Captain America’s decision to stay in the past and the choices he made there.

Steve Rogers had the important mission of returning the Infinity Stones at the exact moment the Avengers got them to preserve the timeline. However, his decision to stay in the past and build a life with Peggy Carter there led to a major branched timeline being created. This version of the MCU would have had Steve Rogers active during the long period he was frozen in the main MCU timeline. With years of events being affected by Captain America, that timeline could have led to other MCU characters making different choices, resulting in Downey being Doctor Doom, not Iron Man.

Captain America’s Avengers: Endgame Ending Could Connect To The Fantastic Four

Doctor Doom Is Not The Only Character That Could Be Impacted By The Theory

The Avengers: Doomsday theory also makes it possible for Evans’ Captain America to be linked to Doctor Doom’s biggest adversaries, the Fantastic Four. In the branched timeline created by Steve Rogers, the character could have carried on being Captain America, working alongside Peggy to make the world a better place as she was turning SHIELD into the powerhouse it would become. With that joint effort, it is possible that Earth would have thrived way before the MCU’s timeline. As such, Captain America’s timeline could lead to the MCU’s Fantastic Four, who live in a retro-futuristic New York in the 1960s.

Given how Chris Evans’ Avengers: Doomsday role is being kept a secret for now — Marvel has not even officially announced the casting yet — perhaps the answer to the questions surrounding his return will only be answered when the project starts filming this spring. However, as the MCU has explored other alternate timelines in projects like Loki and Doctor Strange in the Multiverse of Madness, it would make sense for Captain America’s decision to stay in the past to bring along fundamental changes to his new timeline, including the birth of Robert Downey Jr.’s Doctor Doom, the star of Avengers: Doomsday.

All Announced Upcoming MCU Movies

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  Captain America: Brave New World

  Release Date

  
  February 14, 2025
  

  
  
  
  

  
  

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  Thunderbolts*

  Release Date

  
  May 2, 2025
  

  
  
  
  

  
  

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  The Fantastic Four: First Steps

  Release Date

  
  July 25, 2025
  

  
  
  
  

  
  

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  Avengers: Doomsday (2026)

  
  
  
  
  

  
  

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  Spider-Man Homecoming 4

  Release Date

  
  July 24, 2026
  

  
  
  
  

  
  

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  Avengers: Secret Wars

  Release Date

  
  May 7, 2027
  

  
  
  
  

  
  

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