Donnie Wahlberg’s Blue Bloods spinoff Boston Blue recasts Sean Reagan as the character takes on a bigger role in a new city and storyline.
Blue Bloods fans, brace for a big change—Donnie Wahlberg is back as Danny Reagan, but his on-screen son will look a little different this time around. As Wahlberg leads the upcoming CBS spinoff Boston Blue, the role of Sean Reagan has officially been recast.
After portraying Sean for 14 seasons, Andrew Terraciano will not return in the new series. Instead, the role has been handed to rising actor Mika Amonsen, who steps in as the now-grown son of Danny Reagan.
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In Boston Blue, Danny leaves New York behind for a new chapter in Boston, and Sean’s story will continue alongside him. While Sean was still in high school during the Blue Bloods finale, the spinoff will present him as a Boston police patrolman. He’s following in the Reagan family’s footsteps—but with his own spin. According to early details, Sean’s journey will play a central role in the narrative as he and Danny get a fresh opportunity to reconnect as father and son.
Amonsen, most recently seen attending the LA fan screening of Thanksgiving, will take on the challenge of continuing Sean’s legacy, and fans will be watching closely to see how he brings new life to the character.
Terraciano, who played Sean for over a decade, has not spoken publicly about the recasting. However, following the Blue Bloods finale in December 2024, he shared heartfelt messages about his time on the show. “It feels like, after 15 years, ‘family’ isn’t a big enough word,” he wrote. “Sean Reagan, I let you go.”
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The cast of Boston Blue is already shaping up to be stacked, with Sonequa Martin-Green, Gloria Reuben, Maggie Lawson, Marcus Scribner, and Ernie Hudson joining Wahlberg and Amonsen.
And while no other Blue Bloods characters have been confirmed to appear just yet, one name is on everyone’s mind—Tom Selleck, who played Danny’s father, Commissioner Frank Reagan. Wahlberg recently teased the possibility, saying, “New York and Boston are really close,” before emphasizing how much the Blue Bloods legacy still means to him.
“Letting Danny be a fish out of water in this new world is fun,” Wahlberg said. “But it’s also important to remember where he comes from.”
As Boston Blue begins a new chapter, it’s clear that the Reagan family saga is far from over—just evolving.
