The British actress, who played Steve Rogers's (Chris Evans) love interest Peggy Carter in the Marvel blockbuster, admitted that she would be keen to reprise the role and explore the character further.
"I haven't been approached for Captain America 2 yet, we haven't even spoken about it," she said. "If they did want me to do it I would love to be involved though and have a chance to develop the character of Peggy."
Captain America leads straight into The Avengers, with World War II hero Rogers getting revived in the present day for the Avengers initiative.
Atwell revealed that she won't appear in Joss Whedon's superhero ensemble, either in flashback or as an elderly Carter: "I would love to have been part of it, although not being in it has freed me up from the franchise which allows for a little more creative freedom in my career."
Captain America screenwriter Stephen McFeely recently disclosed that the sequel will stay in the modern day.
"I think it's safe for us to say that it's primarily set in the modern day," he said. "That seems to have been the biggest question people have been wondering about regarding the sequel.
"We've been left with room to explore Cap entering the modern day wondering, 'What is all this? What's happened to the world?' and so on."
Captain America: The First Avenger is available on Blu-ray 3D, Blu-ray Triple Play and DVD on Monday, December 5.
Watch the Captain America trailer below: