Linda Blair, who played Regan in the original Exorcist, served as an advisor on the new film, The Exorcist: Believer, to ensure the safety of the young cast members during intense sequences. Blair was not interested in reprising her role as Regan in any significant capacity, allowing the new film to focus on new characters in a new story. The Exorcist: Believer is a direct sequel to the original 1973 movie, and will feature the return of the demon Pazuzu and Ellen Burstyn as Chris MacNeil.

The Exorcist: Believer director David Gordon Green reveals that Regan actor Linda Blair played an important role during the making of his upcoming sequel. Released in 1973, William Friedkin's The Exorcist introduces Blair as Regan, a young woman possessed by a powerful demon. After several sequels, the first of which saw Blair reprise her role, Green is now set to continue the story in his own trilogy for Blumhouse.