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,

Donnie Wahlberg’s character from the crime procedural, Danny Reagan, will be returning along with his son, Sean Reagan. However, Andrew Terraciano, who played Sean during all 14 seasons of Blue Bloods, will no longer be portraying the character.