While Michael J. Fox will always be known for his career-defining role in classic of the 1980s, it’s hard to view this Robert Zemeckis movie in any other than a stone-cold classic. However, its success wasn’t always a sure thing, and the movie’s infamous production troubles and last-minute changes have become the stuff of Hollywood movie history.

Despite these issues, Back to the Future remains a beloved classic that turned Fox and his co-star Christopher Lloyd into some of the most recognizable faces of the decade. Telling the story of the brash teenager Marty McFly and his eccentric, mad scientist best friend Doc Brown’s outrageous time travel escapades, the Back to the Future trilogy represented the perfect blend of family-friendly adventure, comedy, and sci-fi. While Fox was anxious that Back to the Future could ruin his career, the truth was that it would open the door to a level of success he could have never previously imagined.

Michael J. Fox Thought Back To The Future Would Hurt His Career

Marty McFly Would Become Fox’s Most Iconic Role

Many movie lovers will be well aware that Michael J. Fox didn’t gain his role as Marty McFly in the traditional manner and was actually brought in as a last-minute replacement after the original actor didn’t work out. Eric Stoltz was the original Marty in Back to the Future, but he did not have the comedic temperament that was required, and he was fired from the movie. This was where the original first choice for Marty came back in, and Fox took up the role while simultaneously fulfilling his commitments as a major character on the sitcom Family Ties.

Fox took on a lot at once when he agreed to Back to the Future in the middle of its production, as they went back and reshot already filmed sequences. With a grueling schedule that split his week between film and television work, Fox later told Variety that he was “running on adrenaline” and “I barely knew where I was.” As a young star who was unexpectedly dropped into a haphazard situation with which he was totally unfamiliar, it’s fascinating how Fox’s genuine bewilderment added to his characterization of Marty going on a similarly unpredictable adventure.

Fox was worried that taking on so much at once could negatively impact his career.

Fox agreed that his exhaustion during the filming of Back to the Future likely worked in his favor because “Marty’s supposed to be disoriented.” As a prime example of how a negative can be turned into a positive, it’s incredible how Fox was not only right for the role but also immediately turned Marty into one of the most beloved teenagers in all of cinema. Fox was worried that taking on so much at once could negatively impact his career, but it turned out to be the best decision he ever made.

Michael J. Fox Was Worried About His Performance In The Film

Fox’s Exhaustion On Set Actually Helped His Performance

With so much on his plate, Fox was very worried about his role in Back to the Future and thought his exhaustion on set would lead to a lackluster performance. Fox even said (via Syfy) that he felt his time on Back to the Future would lead to some serious setbacks in his career, stating, “I thought [after] they'd see what I'd done, I'd go back to the back of the pack and start again.”

The success of Back to the Future led to two back-to-back sequels, Back to the Future Part II (1989) and Back to the Future Part III (1990).

Not only did Back to the Future turn Fox into an overnight sensation, but it also led to two beloved sequels that expanded upon the story of Marty and Doc. Fox’s co-star Christopher Lloyd has always praised Fox and said that, despite being worried about not being as good when reshooting six weeks of scenes, “Michael made me better.” While Fox may have been worried that the role of Marty McFly could have ruined his career, the truth was that it altered the timeline for the better and turned Fox into a true icon of the 1980s and beyond.

Source: Variety, Syfy