
Four key Marvel characters who were in early drafts of Thunderbolts* were eventually removed from the script, including one character who could have changed the course of the movie entirely. Thunderbolts* brought the first true team-up movie to the MCU for the first time since Avengers: Endgame, featuring characters such as Yelena Belova, John Walker, Ghost, Winter Soldier, and Red Guardian.
Four Major MCU Characters Who Were Cut From Thunderbolts*
As the script for Thunderbolts* got further along in the creative process, some storylines changed, resulting in characters who were originally planned for the film to be removed entirely.
Kang the Conqueror

For quite some time, Jonathan Majors' Kang the Conqueror was being set up as the main antagonist for the MCU following the death of Thanos. Kang appeared in both seasons of Loki and in Ant-Man and The Wasp: Quantumania, and was even in an early draft of Thunderbolts*.
According to Thunderbolts* writer Eric Pearson in an interview with IGN, an early draft of the film's script featured a post-credits scene that included Kang:
"So I was throwing together at the beginning a post-credit sequence that had to deal with Kang."
Pearson did not reveal any details about what the scene might have showcased, but it was most likely shelved after Majors was fired by Marvel Studios in the midst of his legal issues.
Baron Zemo

Any fans of the source material for Thunderbolts* will know that Baron Zemo played an integral role in putting the team together. So, it is no surprise to learn that Zemo was in early drafts of the film, and that he had an incredibly important role.
While speaking to Screen Rant, Eric Pearson revealed that, in one version of Thunderbolts*, Zemo was revealed to be the mastermind behind everything. One draft even included Zemo as Valentina's assistant (who, in the final cut, is Mel, a character who may be more important to Marvel's future than some may think):
"I think there was a version of a tag written a long time ago, kind of revealing who's behind it all. It was revealed that Baron Zemo was pulling some strings from prison or whatever. I might be just inventing things now, but I feel like there might've been a version where a tag where Zemo had broken out and swapped places with someone - maybe Valentina's assistant - and he was working with a Widow mask under."
At the end of the day, Pearson revealed that Zemo "just didn't fit" into the story they wanted to tell with Thunderbolts*, even though there was "always the discussion" of including him:
"There's always the discussion of, 'Well, if there's a way to cleverly include Baron Zemo in this, he absolutely should be there.' But in this story that we wanted to tell and that we fell in love with, Yelena was central, and all of these people find their way through Yelena. And then we were introducing Bob as well, so he just didn't fit. We didn't want to just have a feathered fish."
Bill Foster

One MCU character some may have forgotten about is Laurence Fishburne's Bill Foster from Ant-Man and The Wasp. The character only appeared in that one film (and in the What If...? Disney+ series) and was closely tied to Ghost.
In an interview with IGN, Eric Pearson also revealed that Bill Foster was being considered for a role in Thunderbolts*. Foster even made it into the script at one point before being removed.
According to Pearson, "Foster was involved for a bit as part of the Ghost storyline," but he didn't reveal why Foster was cut:
"There was a version where Bill Foster was involved for a bit as part of the Ghost storyline, and there was a version at first where he was not involved and we brought him in I think in the second draft."
Those who have seen Thunderbolts* will know that a lot of the movie centers around the main characters' past trauma. It is possible that Ghost was being considered for a flashback scene that would have featured Foster.
Man-Thing

Man-Thing has only appeared in one MCU project (Werewolf By Night), but that didn't stop Thunderbolts* director Jake Schreier from lobbying for the character to be included in Marvel's latest team-up film.
According to Schreier, in an interview with SFX magazine, "there was a point during pitching" where the director asked for Man-Thing to not only be included in the film but also be a part of the Thunderbolts team:
"I think there was a point during pitching when I really wanted Man-Thing to be on the team."
Obviously, Man-Thing would have stuck out like a sore thumb on the team of misfits, and he likely never even made it into one of the scripts, but many would probably think his inclusion could have been interesting, to say the least.
BONUS: Melina

Since Thunderbolts* was released, many fans have wanted to know where Rachel Weisz's Melina is, especially considering Yelena and Alexei (Red Guardian) played such major roles in the movie.
While there has been no confirmation that Melina was ever included in any versions of the Thunderbolts* script, David Harbour and Florence Pugh have both expressed their wishes for Melina to be brought back into the MCU at some point in the future.
In a sit-down with The Hollywood Reporter, Harbour revealed that he has "talked to people about Melina" and that he thinks there is "potential" for her to return:
"I’ve talked to [Marvel] people about Melina, and I think there’s still very much potential for Melina."
Pugh echoed Harbour's thoughts by stating she "hopes" Melina is brought back into the fold, but Harbour continued by saying he "would love to have her back in Alexei's life:"
"But I do think that there’s potential for Melina’s reemergence in some kind of interesting way, and I would love to have her back in Alexei’s life. She would add such an interesting complexity."
Melina survived the events of Black Widow and seemingly rekindled her relationship with Alexei in a deleted scene, but no update on her whereabouts or status has been given since.