Although “Boston Blue” is a direct offshoot of “Blue Bloods,” the Reagan family will look a bit different this time around. Mika Amonsen has joined the CBS drama in a series regular role playing the youngest son of Donnie Wahlberg's character,

Mika Amonsen ( Thanksgiving) has joined the show’s cast as Sean Reagan, the youngest son of series lead Donnie Wahlberg’s character, Danny Reagan. Amonsen will take over the role played by Andrew Terraciano throughout Blue Bloods’ 14-season run on CBS.