When Blue Bloods fans learned that the Reagan family’s legacy would continue in the upcoming spinoff Boston Blue, excitement spread quickly. Donnie Wahlberg’s return as Detective Danny Reagan gave viewers a sense of continuity, but one major change sparked intense discussion online: the recasting of Danny’s son, Sean Reagan.
For fourteen seasons, Sean — Danny’s youngest child — was portrayed by Andrew Terraciano. Audiences watched him grow up alongside the rest of the Reagan clan, making him a familiar face at the family dinner table. So when Paramount+ announced that the spinoff would feature a new actor, Mika Amonsen, in the role, fans were both curious and cautious.
Now, the show’s creators are explaining why this decision was made, what it means for the story, and how the recasting represents more than just a change in appearance — it signals a new phase for the Reagan legacy.
A Time Jump and a Fresh Start
According to Boston Blue showrunners Brandon Sonnier and Brandon Margolis, the decision to recast Sean Reagan came naturally from the show’s timeline. The spinoff takes place several years after the events of Blue Bloods’ final season, during which Sean was still a teenager finishing school. In Boston Blue, Sean is now a young adult, entering the police academy and preparing to follow in his father’s footsteps.
“We wanted to show time passing in a real, believable way,” said Sonnier. “Danny’s life has moved forward. His kids have grown up, and Sean’s story is at a very different stage now. That change felt like the right moment to bring in someone who could portray the next chapter of that journey.”
The producers describe the series as both a continuation and a reinvention. Moving the story from New York to Boston created an opportunity to explore new dynamics — not only between Danny and his new colleagues but also within his family. “Sean’s arc is crucial,” Margolis added. “He’s not the kid at the dinner table anymore. He’s a man trying to live up to the Reagan name, and that comes with pressure, pride, and a lot of heart.”
Why Mika Amonsen Was Chosen
Newcomer Mika Amonsen’s casting caught attention partly because he’s relatively unknown — a fresh face in a world filled with television veterans. But the producers say that’s exactly what they wanted.
“We didn’t want someone who felt like a copy of the past,” explained executive producer Jerry Bruckheimer. “We wanted an actor who could make Sean feel new, while still carrying the warmth and resilience that define the Reagan family. Mika had that quality right away — he felt grounded, thoughtful, and genuine.”
During auditions, Wahlberg himself reportedly read scenes with Amonsen, helping to test their on-screen chemistry. The result impressed everyone. “There was this moment where Donnie looked at him after a take, and you could tell — he saw his character’s son in him,” said Margolis. “It wasn’t about replacing Andrew Terraciano; it was about building the next version of Sean.”
Amonsen’s Sean is older, more independent, and torn between the ideals he grew up with and the realities of modern policing. His story explores what it means to grow up in the shadow of a legendary law enforcement family — and to define your own moral compass in the process.
The Challenge of Recasting a Beloved Role
Recasting is always a delicate subject, especially for a show with as loyal a fanbase as Blue Bloods. But the creative team knew they couldn’t shy away from it. “It’s a natural part of storytelling,” Bruckheimer explained. “Characters evolve, actors move on, and sometimes time itself demands change. The key is to approach it with honesty.”
Margolis said the writers didn’t want to ignore the recast but rather integrate it meaningfully. “When fans see Sean for the first time, it’s acknowledged that he’s older, that he’s been through things we didn’t witness on screen. That sense of growth is what grounds the change.”
The decision also reflects a broader creative strategy: to ensure Boston Blue stands on its own rather than feeling like a direct continuation of Blue Bloods. “The show respects its roots,” Sonnier said, “but it’s not about repeating them. We want new viewers to connect just as easily as longtime fans.”
Donnie Wahlberg’s Support and Perspective
For Wahlberg, who’s portrayed Danny Reagan since 2010, the recast is less about replacing and more about reimagining. “Andrew will always be part of this family — on and off screen,” he said in a recent interview. “But this is a new story. Danny’s in a new city, his son’s grown up, and life has changed. That’s what the show is about: change, growth, and keeping the heart of the Reagans alive wherever they go.”
Wahlberg has publicly praised Amonsen’s work ethic and emotional depth. “He’s a great kid — really talented, really humble. I saw a lot of myself in him when I started out. He brings something new, and I think fans are going to love where Sean’s story goes.”
How Fans Are Reacting
Online reaction to the recasting has been largely positive. While some longtime viewers admitted they were initially hesitant, many praised the creative choice after seeing early footage. Discussions on fan forums highlight Amonsen’s resemblance to Wahlberg and his ability to capture the same mix of stubbornness and sincerity that defined Sean as a boy.
Social media sentiment also suggests that audiences appreciate the show’s willingness to evolve. One fan wrote, “If Boston Blue is about growth, then Sean growing up — and being played by someone new — makes perfect sense. It feels natural, not forced.”
The Future of the Reagan Legacy
As Boston Blue continues its first season, Sean Reagan’s journey is expected to become one of its emotional cornerstones. His efforts to earn respect as a young officer while living up to the Reagan name create an intergenerational tension that mirrors what made Blue Bloods so compelling.
The show’s creators have hinted that other familiar faces from the original series may appear later, but they insist the spinoff’s focus will remain on Danny and Sean’s evolving relationship. “This isn’t just a police show,” Sonnier concluded. “It’s about fathers and sons, legacy and loyalty, and the way family shapes who we become — no matter where life takes us.”
