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.

Mika Amonsen will play Sean Reagan in the 'Blue Bloods' spinoff, 'Boston Blue,' a role previously played by Andrew Terraciano.

CBS’s upcoming “Blue Bloods” spinoff has recast Danny Reagan’s son after the same actor played the recurring role throughout the original 14 seasons. Andrew Terraciano will not return as Sean Reagan in “Boston Blue” after appearing in nearly every episode across 14 seasons as the son of Donnie Wahlberg’s character,