Hayley Atwell's Peggy Carter has seen her character's life expanded upon in the Marvel Cinematic Universe since her initial appearance in Captain America: The First Avenger. Not only did they find a way to include Peggy in both Captain America sequels -- albeit the latest saw her character's funeral -- but they managed to bring her back for a cameo in Avengers: Age of Ultron as well as the opening flashback scene for Ant-Man. Atwell, of course, also led an Agent Carter television series on ABC for two seasons before the network cancelled it due to poor ratings. Yet, while the character has seen a long life on screen, fans have been eager to see Atwell return and if speculation proves to be true? They could just get their wish.RELATED: Avengers 4: Brie Larson Arrives For Filming.To understand the speculation, we'll need to look back on a set of tweets from Marvel Studios co-president Louis D'Esposito from back in July in which Atwell paid a visit to studio headquarters and posed for a pair of photos alongside D'Esposito.

Although D'Esposito's tweets seemed innocent enough at the time, they were enough to send fans into a frenzy leading many to think the actress had paid a visit to discuss a potential return for her character whether it be for another flashback in Ant-Man and the Wasp and/or the next two Avengers films. However, speculation seemed to die down a bit after it was revealed Atwell had booked a role in Disney's Christopher Robin, with the actress seemingly being booked with both that and the Starz and BBC’s Howards End miniseries she'd been busy filming over the summer. And then a brand new casting call was released back earlier this month that kicked the speculation off again.

On September 15th, Central Casting took to Facebook to post a new casting call for a movie working under the title of Mary Lou -- which has been confirmed to be Avengers: Infinity War and Avengers 4 for sometime now -- stating the production was looking for women to portray engineers in a small scene. Interesting? Sure. But it was the requirements for those applying that were all the more interesting as the casting call specifically stated "no dye, no modern colors or cuts" suggesting the scene in question would be for a flashback. That, naturally, led many to assume the studio had found a way to bring Atwell's Peggy Carter back.

And then yesterday, Atwell took to Instagram to post a photo of her wearing mo-cap dots while on a set.

While some were quick to suggest the mo-cap dots were for Atwell's role in Christopher Robin, it's worth noting Atwell's role in that film is that of Robin’s wife, meaning mo-cap wouldn't be needed. However, if Peggy Carter were to be brought back for a scene in Avengers: Infinity War? It's entirely possible she'd need the mo-cap dots if they planned on aging her up like they did in Captain America: The Winter Soldier or Ant-Man. At this point, it's all merely speculation, however, everything seems to point to the possible return of Peggy in the Marvel Cinematic Universe and that's always a good thing.

RELATED: Avengers 4: Every Character We Know Is in the Movie (So Far).

Avengers 4 is currently filming in Atlanta, Georgia.

Directed by Joe and Anthony Russo, Marvel’s Avengers: Infinity War stars Robert Downey Jr., Josh Brolin, Mark Ruffalo, Tom Hiddleston, Chris Evans, Chris Hemsworth, Jeremy Renner, Chris Pratt, Elizabeth Olsen, Sebastian Stan, Benedict Cumberbatch, Paul Bettany, Samuel L. Jackson, Cobie Smulders, Benedict Wong, Zoe Saldana, Karen Gillan, Vin Diesel, Dave Bautista, Pom Klementieff, Scarlett Johansson, Tom Holland and Anthony Mackie. The film opens May 4, 2018.

(via ComicBookMovie)