One of the greatest assets of the reportedly turned her down immediately when she first proposed Chris Pratt for the role of Peter Quill — but they often end up being the perfect actor for their chosen part.

RELATED: MCU: 10 Actors Who Should've Been Given Bigger And Better Roles

Although a lot of Marvel’s actors have been perfect for their roles, they’ve rarely been the producers’ first choice. A number of actors have turned down Marvel roles, or given unsuccessful auditions for the studio.

Perfectly Cast: Robert Downey Jr. As Tony Stark

Tony Stark in Avengers Endgame

It’s hard to imagine now that Marvel has made him possibly the biggest movie star in the world, but casting Robert Downey Jr. as Tony Stark in Iron Man was considered to be a risk at the time, given the actor’s then-recent difficulties with addiction.

No one but Downey could make a “genius billionaire playboy philanthropist” feel relatable and human. Martin Scorsese may not respect Marvel movies as “cinema,” but Downey’s heartfelt performance in Avengers: Endgame provided fans with endless emotional catharsis.

Almost Cast: Tom Cruise

Deepfake of Tom Cruise as Iron Man

A deepfake has been made with Tom Cruise taking Robert Downey Jr.’s place as Tony Stark in a ton of the MCU’s most memorable moments because the shortlist for the role reportedly came down to Downey and Cruise before Downey was cast.

In the years since, both Cruise and Marvel have downplayed how close Cruise came to getting the part, but he was under serious consideration at one point.

Perfectly Cast: Chris Evans As Steve Rogers

Steve Rogers holding Mjolnir in Avengers Endgame

Portraying Captain America on the big screen was a unique challenge because it’s tough to make a character who’s morally pure compelling and he borders on blind jingoism from time to time, but Chris Evans made it look easy.

Evans’ likability knows no bounds, which fits the role of goody-two-shoes Steve Rogers like a glove, and he made Rogers consistently captivating despite the character’s generally squeaky-clean image.

Almost Cast: John Krasinski

Jim Halpert making a funny face to the camera on The Office

John Krasinski was one of the actors up for the role of Steve Rogers in the MCU’s early stages of development. Apparently, when Krasinski saw the hulking physiques of both Chris Evans and Chris Hemsworth, he knew he wasn’t going to land the part.

RELATED: MCU: 5 Actors Considered To Play Iron Man (& 5 For Captain America)

Now, Krasinski and his real-life wife Emily Blunt (who turned down the roles of both Black Widow and Peggy Carter) are popular fan castings for the MCU’s Reed Richards and Susan Storm.

Perfectly Cast: Zoe Saldana As Gamora

Gamora inside the Milano in Guardians of the Galaxy

After playing Uhura in the Star Trek reboot and Neytiri in James Cameron’s Avatar, Zoe Saldana had become a go-to leading lady for sci-fi blockbusters. Naturally, she came onto Marvel’s radar when the studio was developing Guardians of the Galaxy.

Saldana has brought plenty of nuance to Gamora’s characterization, drawing on her tragic backstory and developing palpable bonds with her on-screen sister Karen Gillan.

Almost Cast: Amanda Seyfried

Amanda Seyfried in Mamma Mia! Here We Go Again

Amanda Seyfried is one of the biggest movie stars to not yet have played a superhero in one of the franchises that are currently dominating Hollywood. But she did reveal that she was offered the role of Gamora in Guardians of the Galaxy.

However, getting painted blue for the X-Men movies was a nightmare.

Perfectly Cast: Chris Hemsworth As Thor

Chris Hemsworth in Thor Ragnarok

Although Thor was one of the MCU’s most boring characters in the franchise’s early days when the writers involved didn’t know how to make him interesting, Chris Hemsworth still brought his all to the role. And since Taika Waititi revitalized the character with Thor: Ragnarok, Hemsworth’s performances as the God of Thunder have been even greater.

After giving Thor a comedic makeover in Ragnarok, Hemsworth brought real depth and humanity to the character’s new form in the next two Avengers movies.

Almost Cast: Daniel Craig

Daniel Craig as James Bond

Somewhat surprisingly, Marvel’s first choice for the role of Thor was Daniel Craig, but the actor turned down the part due to his commitments to the James Bond franchise.

RELATED: MCU: 5 Actors Considered To Play Thor (& 5 For The Hulk)

Before Hemsworth was cast, the studio considered Brad Pitt, Channing Tatum, Joel Kinnaman, Charlie Hunnam, Alexander Skarsgård, Kellan Lutz, and even Tom Hiddleston for the role of Thor.

Perfectly Cast: Chadwick Boseman As T’Challa

Chadwick Boseman as T'Challa in Black Panther looking over the battlefield.

The world suffered a huge loss earlier in 2020 with the sudden ing of Chadwick Boseman. Black Panther was a cultural landmark that will inspire generations to come and Boseman truly embodied the eponymous king.

It’s unclear how Marvel will handle Boseman’s ing, with some suggesting Shuri as the next Black Panther, but one thing for sure is that Boseman cannot be replaced.

Almost Cast: Wesley Snipes

Wesley Snipes as Blade showing off his fangs

Wesley Snipes developed a Black Panther movie long before the MCU took over the film industry. In the early ‘90s, before taking on the role of Blade, Snipes planned to star in a Black Panther movie for director John Singleton.

However, studios were unsure about the commercial viability of superhero movies at the time and, on top of that, when a lot of executives who hadn’t heard of the comic book were pitched the project, they thought it was a movie about the Black Panther Party.

NEXT: 10 MCU Actors That Previously Starred In Other Marvel Movies