Black Widow will be set between Captain America: Civil War and Avengers: Infinity War which means that a lot of MCU stars could make an appearance and ScreenRant has a theory that Bucky Barnes will be in the film.
It turns out that Black Widow and the Winter Soldier have a history in the comics, but not the MCU.
In the films, Natasha tells Steve Rogers about the Winter Soldier, saying that many believe he’s a ghost story, but she’s actually crossed paths with him in Iran while on a mission. She reveals that she went after him but it was a “dead end”.
She even mentions that the Winter Soldier “could at least recognise” her during a fight in Captain America: Civil War.
In the comics, the pair has a very different relationship.
Bucky was actually one of Natasha’s trainers in the Red Room and then years later they got together romantically, which I was totally not expecting. Upon Googling the pair I found a lot of fanfic, so clearly this would be something the fans would like to see, however, it’s unlikely that storyline would make it into the movies.
In the MCU, Bucky is put into a cryogenic sleep between Civil War and Avengers: Infinity War, however, he could still appear in the film in flashbacks.
They could potentially show Natasha’s first encounter with the Winter Soldier and then her search for him afterward or maybe even have the reveal of him being her Red Room trainer?
Either way, we’re even more excited to see Black Widow and Falcon & The Winter Soldier when they’re released next year.