AceShowbiz - "This Is Us" has added "I'm Dying Up Here" actor Michael Angarano to its cast for the upcoming third season. Angarano is cast as Nicky, the brother of Jack (Milo Ventimiglia).

Nothing much is known about the character, but Jack and Nicky served together in Vietnam, where the latter died during the war. Nicky was first seen in season 2 episode titled "Brothers". The episode saw Jack staring at a photo of himself with Nicky in Vietnam.

The arrival of Nicky in the family drama's upcoming season is expected as season 3 is set to delve into Jack's time in Vietnam. It was hinted in season 2 finale, in which Kevin (Justin Hartley) and his new girlfriend Zoe were seen heading to Vietnam in a flash-forward scene.

Hartley previously revealed that the revelations of Jack's time in the country were "super-heartbreaking" and "shocking." He added, "It's not what anyone is expecting. No one is going to see it coming." Meanwhile, Ventimiglia shared that his first reaction learning the story of his character in Vietnam was, "Holy s**t, holy s**t!"

In order to give an accurate portrayal of the war, the Emmy-nominated series tapped renowned Vietnam journalist and author Tim O’Brien ("The Things They Carried") as consultant. In addition to sharing his experience, O’Brien is also co-writing with Dan Fogelman an early episode that “really dives into Jack’s life,” according to co-showrunner Isaac Aptaker. Aptaker added, “We are going to be spending a lot of time in Vietnam” this season.

"This Is Us" is the latest work to be added in Angarano's resume. His credits include Jennifer Morrison's "Sun Dogs", in which he stars opposite Melissa Benoist, and Emma Roberts-starring "In a Relationship".

Also starring Mandy Moore, Sterling K. Brown, Chrissy Metz and Susan Kelechi Watson, "This Is Us" season 3 kicks off on September 25 on NBC.