Mika Amonsen will replace Andrew Terraciano, who played Sean Reagan throughout the 14-season run of "Blue Bloods."Though Donnie Wahlberg is the only member of the core Blue Bloods cast set to return for the long-running series' first spinoff,

Danny Reagan will return to our TV screens, but his son Sean will look a little different. The role was recently recast as

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