Sebastian Stan Answers What Would Have Happened If Steve and Bucky Went to Vormir in Avengers: Endgame

Avengers: Endgame star Sebastian Stan believes Bucky's lifelong best friend Steve Rogers (Chris Evans) would have sacrificed himself on Vormir if the pair were tasked with retrieving the Soul Stone instead of Black Widow (Scarlett Johansson) and Hawkeye (Jeremy Renner).

"Wow. [Steve] would probably be like, 'I got this.' And [Bucky] would have been like, 'No, I should be doing this,'" Stan said at Italy's Jus In Bello convention when asked which hero would have died to win the Soul Stone, needed to reverse the snap committed by Thanos (Josh Brolin) that erased half of all life in the universe.

"No, I think it would have been a fight, and I probably would have tried to — I should be the one, after everything, to take the leap, so to speak. But knowing him, he probably wouldn't let me. But I don't know, that's a crazy question. Jesus. And then the Red Skull was there."

The stone is unlocked only through its prospective owner making an irreversible sacrifice. Says stonekeeper Red Skull (Ross Marquand), "In order to take the stone, you must lose that which you love. A soul for a soul."

Thanos was forced to sacrifice favorite adopted daughter Gamora (Zoe Saldana), murdering her on the desolate planet. Former S.H.I.E.L.D. partners Black Widow and Hawkeye battled to win the right to commit suicide by leaping off a cliff, a sacrifice ultimately made by Black Widow.

Speaking to the New York Times, Avengers screenwriters Christopher Markus and Stephen McFeely revealed an alternate version would have seen family man Hawkeye die in Black Widow's place.

"Jen Underdahl, our visual effects producer, read an outline or draft where Hawkeye goes over. And she goes, 'Don't you take this away from her.' I actually get emotional thinking about it," McFeely said.

Added Markus, "And it was true, it was him taking the hit for her. It was melodramatic to have him die and not get his family back. And it is only right and proper that she's done."

Both Steve and Bucky survive Endgame, which finishes with Steve relinquishing his shield and the mantle of Captain America to right-hand man Sam Wilson (Anthony Mackie).

When addressing that ending, Stan said at the convention the wrapping up of Steve's story and the passing of the torch to Sam was "a good ending."

Stan and Mackie next reprise their roles in Falcon & The Winter Soldier, a live-action television series to debut on the coming Disney+ streaming service.