At the beginning of Season 10, Jesse Spencer's character Captain Matthew Casey left "Chicago Fire" to move to Portland, Oregon. The actor's reasons for leaving were admittedly less dramatic, citing 18 consecutive years of acting on television as a reason to take a much-needed break.

Spencer last appeared in the show’s milestone 200th episode, which aired in October 2021. Despite the episode's sense of closure, the actor was quick to tease his character's eventual return, saying "I think it was pretty organic that he's leaving, and he's going for three years but is he? We don't know.”

Ahead of this season’s finale on May 18, executive producer Derek Haas hinted that Casey could be making an appearance in the Windy City. Another possible hint to his return is that Spencer is listed on IMDB as a cast member for Season 10, Episode 17, set to air April 6.