If you tuned in for the highly anticipated premiere of Boston Blue on CBS last week, you may have noticed something unexpected one familiar Reagan family member looked a bit different.
In a notable casting change, Mika Amonsen has taken over the role of Sean Reagan, the youngest son of Danny Reagan. The character was previously portrayed by Andrew Terraciano, who played Sean throughout Blue Bloods’ remarkable 292-episode run.
Naturally, fans were quick to ask the big question: Why the recast after so many years?
Co-showrunner Brandon Margolis addressed the decision in an interview with Variety, clarifying that the move wasn’t about replacing Andrew or diminishing his long-standing contribution. Instead, it was about shaping a new chapter for the franchise and introducing a fresh direction for Sean’s character.
With a new actor and a renewed focus on the father–son dynamic, Boston Blue is already establishing its own identity
while still honoring the Reagan legacy that made Blue Bloods a beloved staple for more than a decade.