The picture of Stan in his costume as the titular antagonist has been posted on Reddit.
The film will centre on Bucky Barnes (Stan), Captain America's former sidekick who emerges after decades presumed dead as a brainwashed Soviet assassin.
Chris Evans will return in the title role under directors Anthony and Joe Russo.
Scarlett Johansson, Anthony Mackie, Cobie Smulders, Georges St-Pierre, Frank Grillo, Hayley Atwell, Toby Jones, Emily VanCamp, Maximiliano Hernández, Robert Redford, Alan Dale and Samuel L Jackson will also feature in the Marvel Studios sequel.
Captain America: The Winter Soldier will arrive in cinemas on April 4, 2014.
Gallery - Marvel Studios Phase Two preview: