Sebastian Stan is Captain America’s Bucky!

The Hollywood trades got the scoop that Sebastian Stan, one of many whom originally tested for the lead role in Marvel’s The First Avenger: Captain America, has been cast as Bucky Barnes, Cap’s sidekick to the previously-announced Chris Evans.

Like other actors, the star of the CW’s "Gossip Girl" and before that, NBC’s short-lived "Kings," has signed on to do five or six movies, but there’s no word whether that might include any movies set in the present day or whether he’ll appear in some form in The Avengers.

During World War II, Bucky Barnes was a teenage orphan too young to join the army, instead brought to the battlefield as a mascot. There, he discovered Captain America’s true identity and convinced him to be his sidekick. He was subsequently killed while trying to defuse the exploding rocket that presumably also killed Captain America, but instead threw the war hero into the Arctic Circle where he was frozen for decades. Bucky was revived in recent years as The Winter Soldier, having been reprogrammed by the Soviets as an assassin.

With director Joe Johnston at the helm, The First Avenger: Captain America will begin filming in Europe over the summer for a scheduled release of July 22, 2011.

Source: The Hollywood Reporter, Variety