CBS has officially confirmed that actor Mika Amonsen will take over the role of Sean Reagan in its upcoming series Boston Blue, a spinoff of the long-running police drama Blue Bloods. This decision marks a significant shift, as the character was previously played by Andrew Terraciano throughout the original show’s 14-season run.
Terraciano portrayed Sean Reagan, the youngest member of the Reagan family, from a young age. His character often appeared during the show’s weekly family dinner scenes and was gradually seen taking on more responsibility, eventually joining the police force. However, CBS has decided to recast the role for the new series, aiming to show a more grown-up version of Sean in a fresh setting.
The spinoff Boston Blue is currently in development and is being led by Blue Bloods creators Kevin Wade and Siobhan Byrne O’Connor. The new series will continue to explore the Reagan family's legacy in law enforcement but with a focus on younger characters and new storylines. CBS Studios and producing partner Friday Night Dinner Productions are backing the show.
Why CBS Chose to Recast the Role for the New Series
According to reports, the decision to recast Sean Reagan wasn’t made lightly. Andrew Terraciano had been part of Blue Bloods since 2010, playing a key role in many story arcs. But with Boston Blue, the network is reportedly shifting the tone to appeal to a new generation of viewers, while still honoring the spirit of the original series.
CBS stated that Mika Amonsen’s casting allows them to present Sean Reagan as a more developed and mature character. While not much is publicly known about Amonsen, insiders say he impressed during auditions and was chosen for his strong performance and screen presence. The new version of Sean will likely be more central to the show’s plot, possibly taking on bigger responsibilities within the police department or the Reagan family dynamic.
CBS’ ‘Boston Blue’ Adds Mika Amonsen in Recasting From ‘Blue Bloods’ https://t.co/iADK6iMEMH
— The Hollywood Reporter (@THR) July 9, 2025
So far, it’s unclear whether other original Blue Bloods characters will return in Boston Blue. The spinoff is expected to introduce a mix of new and familiar faces, though CBS hasn’t confirmed specific cast details beyond Amonsen. Production timelines and a release date have not yet been announced, but the show is expected to be part of the 2025–2026 broadcast season.
Blue Bloods is scheduled to conclude later this year with the second half of its 14th and final season. The final episodes begin airing in October and will wrap up the series after more than a decade on air. CBS hopes Boston Blue will carry the franchise forward while also bringing something new to long-time fans.
The recasting has sparked conversation among fans of the original series, many of whom grew up watching Terraciano’s performance. But with a new actor stepping in and a fresh direction for the character, CBS is betting on Boston Blue to stand on its own while respecting its roots.
Source(Image / Thumbnail): people
