US-ENTERTAINMENT-PROMISE-PREMIERE"This Is Us" Season 2 is binging in reinforcement -- not that it needs it.

The critically acclaimed drama series has been doing just fine on its own, but that hasn't stopped a big Season 2 cameo from being lined up. Action star Sylvester Stallone is set for a guest role, Variety reports. As of now, he'll only appear in one episode, but showrunner Dan Fogelman called it "a big part" during Thursday's TCA summer press tour.

The cameo is meant to further one of the show's storylines, so we don't expect a reaction of Ed-Sheeran-in-"Game-of-Thrones" proportions. In the episode, Stallone will play himself, and the "This Is Us" version of the actor will cross paths with Kevin (Justin Hartley) as they co-star in a war film. Specifically, Stallone's fictional movie character will bring up certain issues for Kevin.

"Stallone is coming in as himself in the show but playing a character in the film who's a mentor figure who starts bringing up some stuff for Justin's character involving Jack and his relationship with his own father," Fogelman said, according to Variety.

The showrunner also revealed that Stallone will have a "beautiful monologue" and touch on topics like life, aging, and working in Hollywood. That sounds like just the kind of emotional scene you'd expect on the show. You might as well get your tissues ready now.

"This Is Us" Season 2 premieres Sept. 26 at 9 p.m. ET/PT on NBC.

[via: Variety]