(CBR) One of the more intriguing rumors leading up to "Captain America: The Winter Soldier" involved a “twist” that would reveal Robert Redford’s Alexander Pierce as the Red Skull. Of course, that never happened. But is it possible the classic villain could resurface in a another Marvel movie — as soon as the "Winter Soldier" sequel, in fact?

Joe and Anthony Russo, directors of "Winter Soldier" and the upcoming "Captain America 3," spoke with Screen Rant about the possibility of using Red Skull again down the line. They wouldn’t “comment specifically” about the character’s return, but they wouldn’t rule it out, either.

“That’s the great thing about the Marvel universe, is anything is possible,” Anthony Russo said. “All these characters exist. And as we’ve seen on the publishing side, there’s very inventive, creative ways to make characters relevant again and surprising ways to make the characters relevant again. He’s a great character. Whether or not he finds his way back I can’t really say.”

While the Russos wouldn’t confirm or deny a Red Skull comeback, they were considerably more forthcoming about their plans for Bucky Barnes, left alive and unbound from his brainwashing by the end of "Winter Soldier."

“He’s a really complicated character; very tragic, complicated character,” Anthony Russo said. “Here’s a guy, when you look at him, is he the world’s worst assassin or is he the longest serving POW in history? You could look at him as one of two things. Either he’s innocent by reason insanity or the equivalent of that, in terms of not being responsible for his actions because he was brain controlled, or he’s a monster. It’s a very complicated place.”

The Russos will explore those complications in "Captain America 3," in theaters on May 6, 2016.

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