Sean Reagan will be accompanying his father, Danny, to Boston in "Boston Blue," but the series has recast the "Blue Bloods" spin-off's role - here's why.

Andrew Terraciano will not return as Sean Reagan in the spinoff, and Mika Amonsen will now take his place in 'Boston Blue'

Donnie Wahlberg is the new kid on the block in the new Blue Bloods spinoff series, which sees Danny Reagan go to Boston, and they have officially had their first table read. Wahlberg shared a photo of the very first script from his new show,