Wyatt Russell has been cast as John Walker, a.k.a. U.S. Agent, for Disney+'s The Falcon and the Winter Soldier show.
In comic books, John Walker was introduced as a supervillain named Super-Patriot, but came to assume the mantle of Captain America when Steve Rogers quit. Walker gradually became more heroic, and when Rogers took back up the Captain America mantle, he segued into becoming a hero by the name of U.S. Agent.
Russell is best-known for roles in Netflix's Shimmer Lake and Black Mirror. The second-generation actor is the son of Kurt Russell and Goldie Hawn - making him an intergenerational MCU actor, with Kurt Russell having starred in Guardians of the Galaxy Vol. 2.
Here's Disney's official description of the show's portion of the panel:
"Director Kari Skogland introduced Anthony Mackie and Sebastian Stan, the stars of Marvel Studios’ The Falcon and The Winter Soldier,which finds Falcon and the Winter Soldier teaming up after Avengers: Endgame. Emily VanCamp came on stage and Feige revealed that she will reprise her role as Sharon Carter. Then, he introduced the crowd to Wyatt Russell who will play John Walker—a character from the comics coming to the screen for the first time. Head writer Malcom Spellman was also on hand to greet the crowd. The Falcon and The Winter Soldier will launch on Disney+ in 2020. "