Michael J Fox may have been director Robert Zemeckis and screenwriter Bob Gale’s first choice for Marty McFly, but the teen star was too busy with his sitcom Family Ties. Instead, Eric Stoltz was cast, shooting Back to the Future for six weeks before the two Bobs made the tough decision to fire their lead. He may have been a great actor, but sadly he wasn’t the right fit for the light-hearted and comic character they had envisioned.

In the end, a deal was struck for Fox to film Family Ties as usual in the day and then shoot Back to the Future at night. The new Marty McFly would get minimal sleep while being transported between the sets.

Now in a new interview, Doc Brown star Christopher Lloyd has admitted he struggled at first with the recasting news.

The 83-year-old said: “There was another actor and Michael came in after we shot for six weeks. They just decided that they needed somebody with a comic flair, and Stoltz is a wonderful actor, I had no idea that change was coming. One night, we were shooting the mall, beginning sequence. We were all asked to come to one of the trailers at one-o’-clock in the morning and [producer Steven] Spielberg was there and made the announcement of the change. My biggest fear was that, because I was really working to get Doc right, that was the start. I thought, ‘I don’t know if I could get it up to do that again.’ I was worried about it, but it all worked out.”

Fox added: “Then I came across it on TV last Christmas. And I thought I was really good in it, better than I thought I’d been. More important, I got the spirit of the movie.

I understood it was just a big giggle and that we all need… to take credit for what we’ve done and the lives we’ve touched and to occasionally step back a bit and appreciate that much of life has been great and that there’s a lot more to live.”