Donnie Wahlberg confirmed that another Blue Bloods alum is set to appear on Boston Blue after the show recast one of the former cast members. Wahlberg, 56, confirmed at the Television Critics Association panel on Tuesday, January 27, that Len Cariou is returning as Danny's grandfather Henry in an upcoming episode. According to TVLine, Cariou, 86, will make a guest appearance in episode 13 while Erin (Bridget Moynahan) will be featured again in episode 17.