Meet the newest member of the Pearson family.

"This Is Us" has cast actor Michael Angarano as Nicky, sibling to Jack Pearson (Milo Ventimiglia). Angarano currently stars in Showtime's "I'm Dying Up Here" and previously played the son of Sean Hayes' Jack on "Will & Grace" (so, yes, he's going from Jack's son to Jack's brother).

As fans are aware, Nicky served with Jack in the Vietnam War and was killed in action. He was seen briefly as a boy in a flashback scene in Season 2 and again in a photo with Jack and fellow servicemen.

Season 3 will delve into Jack's time in Vietnam. The NBC drama hired  renowned Vietnam journalist and author Tim O’Brien ("The Things They Carried") as a consultant to help the writers create an accurate portrayal.

Jack's service will also be tied into current-day storylines, particularly Kevin's (Justin Hartley), who was seen in a Season 2 finale flashforward traveling to Vietnam with new girlfriend.

"This Is Us' premieres Tuesday, September 25 at 9 p.m. on NBC.