'This Is Us': 'Will & Grace' Star Michael Angarano to Play Jack's Brother

This Is Us is bringing in Will & Grace actor Michael Angarano to play a key role: Jack's brother Nicky.

Angarano's casting was first reported by Deadline. The actor starred on Showtime's I'm Dying Up Here and played the son of Jack (Sean Hayes) on NBC's Will & Grace. He also appeared on The Knick and Mom.

Nicky was first introduced in a flashback scene with Jack (Milo Ventimiglia) when they were children in the season two episode, "Brothers." In that same episode, we saw Jack look at a photo of his brother as an adult in Vietnam. In "The Car," Jack told Randall and Kevin that Nicky died in the war, notes Entertainment Weekly.

Season three is expected to look more into Jack's past and service in the Vietnam War, now that This Is Us no longer has to worry about explaining his death. At the end of season two, we saw Kevin (Justin Hartley) flying to Vietnam with his girlfriend Zoe to learn about his father's experiences.

Last month, This Is Us creator Dan Fogelman told Deadline he is bringing in Vietnam veteran and novelist Tim O'Brien, who wrote The Things They Carry, to help him flesh out Jack's experiences.

"...I just finished actually writing an episode with him that's an entire Vietnam Jack backstory episode, early in our season," Fogelman said. "That's going to be really incredibly exciting and unusual."

Justin Hartley told Entertainment Weekly last week that Kevin's discoveries in Vietnam will shock and surprise everyone.

"It's not what anyone is expecting," he said. "No one is going to see it coming. It's ambitious stuff.... Here's the cool thing about it: At the end of season 3 when you go back and watch the beginning of the series, you're going to [be] like, 'Wow, it all works,' but you never would see any of this coming. I don't know what those writers are eating, but it's brain food. They're brilliant."

During the Television Critics Association press tour, showrunners Isaac Aptaker and Elizabeth Berger teased a "new chapter" and a "whole completely different kind of story" for season three. The show's Vietnam scenes will be a departure for a show mostly set in Pittsburgh, New York and Los Angeles.

"It's different than anything we [or] any of our writers have done in our first two years," Berger told reporters. "To all of a sudden be immersed in the Vietnam War, we think it's going to be really special and really different."

This Is Us season three debuts on Tuesday, Sept. 25 at 9 p.m. ET on NBC.

Photo Credit: NBC