‘Boston Blue’ Bosses Explain Big ‘Blue Bloods’ Recasting

Sean Reagan’s recasting on Boston Blue is finally being addressed.

It was announced in July that Blue Bloods’ Andrew Terraciano would not be returning as Danny’s youngest son, and the character would instead be played by Mika Amonsen.

The offshoot premiered in October and takes place sometime after the series finale of Blue Bloods, which aired in December. In Boston Blue, Donnie Wahlberg’s Detective Danny Reagan comes to Boston after Sean, who is now a rookie in the Boston PD, gets hurt. The casting came as a surprise, but creators Brandon Sonnier and Brandon Margolis explained the decision to TV Insider.

“We wanted a slightly different version of Sean,” Margolis said. “We wanted a character that feels familiar, an actor that does resemble the character that we watched grow up. But as you saw in the pilot, he has made some life changes and having joined the police force, he is really picking up that family mantle.” The two added they wanted to “join the story in progress.”

Terraciano had portrayed Sean on Blue Bloods from beginning to end, appearing alongside big brother Tony Terraciano, who plays Sean’s older brother Jack Reagan. Although Boston Blue is only three episodes in, the series has been putting a lot of focus on Sean already, and the beginnings of him being a rookie cop. The Brandons spoke to PopCulture.com about Boston Blue ahead of the premiere, with Sonnier saying that getting to explore Sean’s dynamic with partner Jonah Silver (Marcus Scribner) is “really exciting.”

“I think their relationship really injects youthful energy into the show,” he said. “It really gives a new look into policing from the ground level in Boston with these two guys who feel like they know a lot because they are from these dynastic families. It’s because they’ve sat around those tables for so many years, but knowing it and doing it are two different things. So we get to watch these guys with a lot of knowledge learn that in the moment, it might not be like it played or when you were talking around the table.”

“They get into, as we like to say, shenanigans, often because they are young and because they are patrol cops, we do get to tell a lot of fun stories with them that bring a level of action that were produced by Jerry Bruckheimer,” he continued. “And then there is an expectation for a heightened level of action in these shows. And we really do get to find it with these two handsome, athletic young men.”

New episodes of Boston Blue air on Fridays at 10 p.m. ET on CBS. All 14 seasons of Blue Bloods are streaming on Paramount+.