Deadline reports that the actors in talks to join Sebastian Stan as Bucky Barnes/Winter Soldier and Anthony Mackie as the Falcon/Sam Wilson are Daniel Bruhl as the villainous Helmut Zemo and Emily VanCamp as government agent and one-time potential Steve Rogers love interest Sharon Carter.
VanCamp made her debut in 2014's Captain America: The Winter Soldier but played a larger role in 2016's Captain America: Civil War, where it was revealed that she was the great-niece of S.H.I.E.L.D. co-founder (and, somewhat cringe-ily, another Rogers love interest) Peggy Carter. She has not been seen in the MCU since.
Bruhl's Zemo, meanwhile -- loosely inspired by the classic Marvel Comics villain Baron Zemo -- was the primary antagonist in Civil War, a vengeful Sokovian soldier who wanted to destroy the Avengers after his family was killed during the battle of Sokovia in Avengers: Age of Ultron. Zemo was taken prisoner at the end of the film, but the potential certainly existed for him to escape.
There is no word yet on how either Zemo or Carter will figure into the plot of the show, but reportedly Sam Wilson accepting Captain America's shield from an elderly and now retired Rogers at the end of Avengers: Endgame will factor into the story as well.
All six episodes of the miniseries, which will reportedly air in August 2020, might be directed by Emmy nominee Kari Skogland, whose credits include episodes of The Handmaid’s Tale, the pilot for the upcoming AMC horror series NOS4A2, Penny Dreadful, The Walking Dead, Under the Dome, The Punisher, and many more.
She would be one of several women taking the reins behind the Marvel cameras as the studio heads into its post-Endgame slate, joining a list that includes Black Widow solo film director Cate Shortland and The Eternals director Chloe Zhao.
The Falcon and the Winter Soldier is one of several MCU-based miniseries being developed for Disney+, along with shows starring Loki (Tom Hiddleston), Scarlet Witch (Elizabeth Olsen), and Hawkeye (Jeremy Renner).