There are a few casting changes being made to Chicago Fire.

On Thursday (January 22), it was reported that Dermot Mulroney, who plays Battalion Chief Dominick “Dom” Pascal, will be going on hiatus for the rest of season 14.

Dermot, 62, will last appear in the upcoming 14th episode, which is set to air in March, with a break that will take him into the end of the season, sources told Deadline. As of right now, it’s unclear if he will be back before the season ends, as scripts for the final episodes haven’t been finalized yet.

Keep reading to find out more…It has been confirmed that Dermot will be appear in the upcoming One Chicago crossover event (episode 13), which set to air on March 4.

Along with news of Dermot‘s hiatus, it has also been announced that Rob Morgan will be joining the cast of Chicago Fire in a recurring role. The 52-year-old actor will be playing Battalion Chief Hopkins, “who has a long, haunted past in overseeing several Chicago firehouses and is quick to assert authority over his colleagues.”

Rob is set to make is debut in episode 16 and will appear in four episodes, including the season finale. Dermot‘s hiatus is a part of his characters storyline and viewers will understand more about Hopkins’ overall rule in the the rest of the season as the story plays out.

You can find out more about the upcoming One Chicago crossover event here!

New episodes of Chicago Fire air on Wednesdays at 9pm ET on NBC.