The Boston Blue creative team is standing by the decision to recast Donnie Wahlberg's son Sean. During the series premiere on Friday, October 17, some viewers may have been surprised to see Mika Amonsen in the role of Sean after the character was originally played by Andrew Terraciano on Blue Bloods. "We love Andrew and the work he did over the years on Blue Bloods. Really, it came down to we're telling a new chapter in both of their lives," coshowrunner Brandon Margolis told Variety.