Matt Casey (Jesse Spencer) is, for many, one of the best characters in Chicago Fire history. He was not without his flaws, but he radiated decency during his time on the show, and managed a positive outlook in even the most dire of situations.
He was the perfect counterbalance to Kelly Severide (Taylor Kinney), who has also been more of a rogue and someone prone to going with his gut. Severide is still around, obviously, but we have all been looking for another Casey. And we may have found our best candidate yet.
Jack Damon is seemingly modeled after Casey
Jack Damon (Michael Bradway) is officially part of Firehouse 51 again. The character was booted at the start of season 13, but brought back into the fold after his half-brother Severide and Stella Kidd (Miranda Rae Mayo) made a request. Damon may be related to Severide, but in temperament and an overall sense of positivity, he's very much cut from the Casey cloth.
The firefighter cares about his fellow firefighters, is brave to the point that it makes cowardly peers from other firehouses insecure, and is romantically interested in a 51 medic. Sounds like Casey to us, given that the former standout is now living in Oregon with Sylvie Brett (Kara Killmer), the medic that Lizzie Novak (Jocelyn Hudon) has replaced.
As you inferred from the headline, there is another Chicago Fire character that Damon reminds us of, and he was actually positioned to be the Casey successor before his sudden departure. We're talking about Blake Gallo (Alberto Rosende). Gallo looked up to Casey, and was absolutely beaming when the latter crowned him part of the "old guard" during the season 11 finale.
The firefighter is part of 51's new generation
Gallo was another excellent firefighter who had an on/off romance with a medic, and given that he served under Casey, his succession was even more obvious. Unfortunately, the character left during the season 12 premiere, and decided to move to Michigan. His tenure was cut short, and the absence of a Casey-like figure has been felt ever since.
Casey and Severide were never going to be able to fight fires forever. Chicago Fire has been on for so long that we are seeing the generation we were introduced to cede ground to the younger generation in an effort to keep things going. Sam Carver (Jake Lockett) has been positioned as a more intense and even more troubled Severide, and Damon, fully reinstated, seems all but locked in to take over Casey's spot. Provided he sticks around longer than Gallo.