Reasons Behind Recasting Donnie Wahlberg's On-Screen Son in "Boston Blue" Revealed: All You Need to Know about Replacing Andrew Terraciano on "Blue Bloods"

Boston Blue, the latest spinoff from Blue Bloods, premiered in October 2025, featuring a major recasting: Mika Amonsen now portrays Sean Reagan, taking over from Andrew Terraciano. The change has sparked varied reactions among fans of the franchise.

Why the Recasting Happened

In July 2025, PEOPLE reported that Terraciano would not return as Sean Reagan, son of Danny Reagan (Donnie Wahlberg), in CBS' new series. Terraciano had played Sean on Blue Bloods for 14 seasons from 2010 to 2024. The decision surprised longtime viewers, given his long-standing presence on the show.

Before the October 17, 2025 premiere, co-showrunner Brandon Margolis explained to TVLine that Amonsen was brought on to provide a different energy for the character. "We loved Andrews work and enjoyed watching him grow up on screen," Margolis said. "But for this new chapter, it made creative sense to find someone who could bring a fresh perspective."

Changes to the Reagan Family Dynamic

Margolis told Variety that the recast was purely a creative choice. In Boston Blue, Sean is now a patrol officer in the Boston Police Department, eager to uphold the Reagan legacy while forging his own identity. Danny moves to Boston and joins the local police, creating a first-time father-son working dynamic within the same department. This setup allows exploration of both family life and police work simultaneously.

"Were telling a new chapter in their lives," Margolis said. "Its the same character, the same relationship, but the circumstances are completely different. Theres a new energy that helps dramatize these changes."

Fan Reactions to the New Sean Reagan

Fans have shown mixed reactions to Amonsen replacing Terraciano. Some expressed disappointment, feeling the original actors absence was unnecessary. One Instagram user wrote, "The change does a real disservice to fans who grew up with the original actor." Others embraced the recast, praising the renewed father-son moments. "The interactions between Danny and Sean have been my favorite part," a fan commented. "Its great seeing Danny adapt to being the father of a cop."

Mika Amonsens Perspective

Amonsen has acknowledged the fan negativity but chooses to focus on positive responses. He told Us Weekly in November 2025, "Fans have been supportive of the version of Sean Ive created, and that makes me happy." He also admitted the role carried "a ton of pressure" and prepared by watching Blue Bloods to maintain Seans signature traits, including his upbeat energy and hairstyle.

Andrew Terracianos Response

Terraciano has not directly commented on the recast but expressed gratitude for his time on Blue Bloods after its final season in June 2024. On Instagram, he wrote about the strong bonds and personal growth he experienced during his 15 years on the show and formally bid farewell to the character of Sean Reagan.

Author: Sophia Brooks