Boston Blue Season 2 Cast Shake-Up: CBS Drama Adds New Faces and a Guest Star from Blue Bloods

• Marg Helgenberger joins the Season 2 stars as Gwen Silver in a guest role. She is the estranged biological mother of Superintendent Sarah Silver (Maggie Lawson). Gwen is described as a “complex yet charming woman whose temperament is not unlike the climate of her Cape Cod home – unpredictable.”
  

• Identical twins Eleanor and Penelope Yataco have been cast to play Elena Baez, the daughter of Detective Maria Baez (Marisa Ramirez). Maria adopted Elena as a baby in the Blue Bloods Season 12 finale, and now she’s finally making an appearance in the spinoff.

Will Estes is set to make his guest-starring debut as Jamie Reagan in Season 2, specifically in Episode 5 of the CBS series. Jamie is Danny Reagan’s younger brother, whom fans may know from Blue Bloods. The casting was confirmed by Donnie Wahlberg, who plays Danny, when he shared an Instagram Story announcing that Season 2 will see Estes reprising his role from the flagship show.

Andrew Terraciano played Sean Reagan throughout all 14 seasons of Blue Bloods, but Mika Amonsen took over the role in the spinoff. Showrunner Brandon Margolis explained the recasting choice to TVLine in a 2025 interview, saying, “Once we realized we were telling a very new chapter in this character's life, creatively it made sense to find an actor with a different energy. Mika's performance calls back to Sean's vulnerabilities, but he brings a youthful energy that takes the character in a new direction we loved.” Amonsen was a series regular in the debut season, and that remains unchanged in Season 2.

• Donnie Wahlberg as Danny Reagan

• Sonequa Martin-Green as Lena Silver

• Maggie Lawson as Sarah Silver

• Marcus Scribner as Jonah Silver

• Gloria Reuben as Mae Silver 

• Ernie Hudson as Reverend Edwin Peters

• Len Cariou as Henry Reagan

• Marisa Ramirez as Maria Baez