Loyal Blue Bloods fans were caught off guard when Danny Reagan’s son, Sean, appeared in the franchise’s new spin-off Boston Blue and not just because the character was recast. Mika Amonsen now steps into the role previously played by Andrew Terraciano, but the real surprise came when viewers learned that Sean is suddenly a police officer, despite showing little interest in law enforcement in the original series.
Boston Blue opens with the episode “Faith and Family,” where Sean is already working the beat in Boston. There’s no explanation for how or why he chose this path, making the career shift feel abrupt. The last time fans saw him on Blue Bloods, Sean was exploring his artistic side, so his jump into policing left many viewers scratching their heads.
Adding to the confusion, the show barely gives Sean time to establish himself before tragedy strikes. Within the first fifteen minutes, he is critically injured while heroically rescuing people from an off-duty fire. Although the moment showcases classic Reagan bravery, Sean spends the remainder of the episode in a coma offering no insight into who this new version of the character is supposed to be.
Fans quickly took to Reddit to express their frustration. “They should’ve made him anything else a lawyer, journalist, firefighter but not a cop,” one viewer complained. Another wrote, “I really hoped Sean would follow his uncle and go to Harvard Law. The reason he and Danny move to Boston doesn’t make sense.”
With Boston Blue already stirring debate, Mika Amonsen faces a challenging road ahead as he works to win over longtime Blue Bloods fans who aren’t sure what to make of this grown-up Sean Reagan or the creative direction of the spin 
off itself.