When "Back to the Future" premiered in 1985, it shot Michael J. Fox to stardom for his much-lauded portrayal of time-displaced teenager Marty McFly.

However, fans of the sci-fi-comedy franchise later learned that the role was almost filled by a different actor, Eric Stoltz, who actually spent a considerable amount of time on set portraying the character.

We're going to take a look back at how the film's cast was almost led by a different star -- and how its crew navigated the aftermath of the shakeup while working on the hit flick.

The casting process for "Back to the Future" proved to be difficult for the project's producers, as numerous talented performers went through auditions for the role.

Various actors -- including Ben Stiller, Jon Cryer and Billy Zane -- all tried out for the lead role in the project.

While the production team took a shine to Fox after he threw his hat in the ring for the part, his professional commitments to the television series "Family Ties," in which he starred, made it seem like he would have been stretched too thin with the movie.

The then-president and CEO of Universal Pictures, Sidney Sheinberg, stepped in and suggested the film's producers cast Stoltz, who'd won him over with his performance in the biographical drama film "Mask."

As a result, the "Some Kind of Wonderful" star was given the starring role, and filming kicked off in November of 1984.

Problems quickly arose on the "Back to the Future" set, as Stoltz's method-acting approach caused conflict with much of the project's cast and crew.

Many of the claims about the actor's behavior were made in author Caseen Gaines' book "We Don't Need Roads: The Making of the Back To The Future Trilogy," originally published in 2015.

The performer's approach to acting caused friction with his costars, as well as what was described in IndieWire as much "frustration and eye-rolls" from the project's crew.

While producer Bob Gale saw Stoltz's way of working as "harmless" as long as he delivered the goods, many others involved in the production of the film viewed the performer as a "pain in the ass."

One of the more troubling incidents occurred during the filming of the a scene in which McFly got physical with school bully Biff, portrayed by Thomas F. Wilson.

According to Gaines, Stoltz got physical with his costar over the course of multiple takes, and actually left his costar with several bruises after the scene was completed.

Lea Thompson, who played McFly's mother, Lorraine Bates, recalled that although Stoltz was a talented actor, his style of acting proved to be too "difficult" for much of the film's cast and crew.

The actress pointed out that while she considered herself to be "really good friends" with her costar, he "wasn’t really a comedian" and didn't provide the right energy for the film.

While the writing was on the wall regarding Stoltz's incompatibility with the cast and crew of "Back to the Future," he remained involved with the project.

However, both Gale and director Robert Zemeckis clandestinely went to Sheinberg to fill him in about the friction on set, after which the studio executive acquiesced to their request to replace the actor.

Stoltz went on to remain involved with the project for several weeks following the producers' decision, however, and remained unaware of their plans to replace him with Fox.

Zemeckis was later given the task of letting Stoltz know about his axing ... and according to Gaines, Eric was particularly disappointed with the decision.

Fox, who ultimately starred in all three "Back to the Future" films, later revealed he'd met and become friends with Stoltz during a panel that took place at Calgary Expo in 2025.

The performer told People he had "learned a lot about acceptance and perseverance" from the actor in the years since the release of "Back to the Future."

Fox also said they'd discussed their switch-up on the set of the film -- which he described as "this turn in our lives" -- at length over the years.