The actor, who earned an Oscar nomination for his performance in 2016 drama "Manchester by the Sea", is starring in Joel Edgerton's new coming-of-age film, in which he plays Jared, a young man forced to take part in a gay conversation therapy programme by his conservative parents, as played by Russell and Nicole Kidman.
Reflecting on the shoot, Lucas admitted that he was rather daunted by the prospect of acting with such established stars.
"I try to do as much work as possible, but when Russell Crowe arrives on set and it's my first time to do a scene with him - and I've never met him before - there is an air of deep intimidation," he said during a video chat for Collider.com. "Which is everything I really need as an actor in that moment. I find that all the true gems, the things that really live in the film, are what's happening immediately in that moment."
"Boy Erased" is based on Garrard Conley's 2016 memoir of the same name.
When researching the role, Lucas carefully studied the book in order to discover the nuances of the author's story.
"The key for me was in studying the book... because you look at photos of Garrard at the time and you can see something's wrong but you can't really tell exactly what. So, it could be anything that's the matter. But when I get to look at the book, I can see specifically what's going on and I just took a lot of inspiration from that," the 21-year-old explained. "He describes at one point the experience of walking into a room (and) that he felt as if he had brought in some dark energy... there was something that people would turn and look at him and see that there was something wrong with him that to me was the epitome of the character for me."
"Boy Erased", also featuring Troye Sivan and Madelyn Cline, is now showing in U.S. cinemas. It hits the U.K. in February.