Donnie Wahlberg Confirms Third Blue Bloods Vet Guest-Starring On Boston Blue — Plus, Two Familiar Faces Return

Another member of the Reagan family is headed to Beantown.

CBS' "Boston Blue" is set to welcome Len Cariou — aka Henry Reagan — for his first appearance on the "Blue Bloods" spin-off, reuniting him with Donnie Wahlberg. Bridget Moynahan, meanwhile, is slated to make her second turn later in Season 1.

Wahlberg let the news slip Tuesday afternoon during a virtual panel hosted by the Television Critics Association. TVLine has since confirmed that Cariou will guest-star in Episode 13, airing in April, while Moynahan — who last appeared in the pilot — will resurface in Episode 17, airing in May.

Matt's Inside Line has also confirmed that Marisa Ramirez will next appear as Detective Maria Baez in Episode 15, likewise airing in April.

Cariou on Blue Bloods (CBS)

"Grandpa Reagan's going to be showing up, and Erin's going to show up again," Wahlberg told reporters while addressing Danny's decision to join the Boston Police Department in Episode 9 — and what it means for the show, as well as Danny's long-distance relationship with Baez, when Season 1 resumes.

"I think there are layers to all this still, right? So there is, of course, Maria, and I think they're figuring things out," he said. "I'm not going to reveal too much... I will just tell you that it's not resolved, and she will be back in the coming episodes," noting that Danny's career change "affects everyone."

"Boston Blue" Season 1 returns with Episode 10 (of 20) on Friday, February 27 at 10 p.m.