Chicago Fire lost many cast members in season 12, including one whose replacement is very exciting, but I still want to see the previous actor back in season 13. The NBC procedural drama TV series has been on the air since October 2012, and over the course of the past 12 years, the cast has undergone several changes. Of course, not every original Chicago Fire cast member is still with the show, with Taylor Kinney as Kelly Severide, David Eigenberg as Christopher Herrmann, Christian Stolte as Randall “Mouch” McHolland, and Joe Minoso as Joe Cruz as the only remaining ones.
https://screenrant.com/chicago-fire-season-13-gibson-return-jack-damon-replacement/