This Is Us" score a knockout casting coup: Sylvester Stallone.

Stallone will be making a series of guest appearances on NBC's emotional family drama, and it was Ventimiglia, who plays the Pearson family's doomed patriarch, Jack, who made it happen. Following Ventimiglia's breakout turn as "Gilmore Girls'" Jess, Stallone tapped the young actor to play the estranged son of the famous underdog prizefighter character in 2006's "Rocky Balboa," and the two would reconnect on occasion in the ensuing decade.

It's a connection the producers of "This Is Us" were highly conscious of when they were looking to cast a key role for the hit show's second season, as Ventimiglia explained to Moviefone and a handful of journalists at the NBC's fall press session for the Television Critics Association, along with previewing how Jack's story advances in the new season.

What was your part in helping make Sylvester Stallone's appearance on the show happen?

Milo Ventimiglia: There's a movie star, a movie idol, that Justin [Hartley's] character is going to be working with, and when I'd heard what the episode was going to be and everything they just kind of looked at me and they said, 'Yeah, someone liked Sly." And I'm like "Cool.' And they go, "Do you think he'll do it?" And I went "I don't know." And they just kept looking at me, and I'm like "Oh -- you want me to call him?"

The nice thing is this: I did "[Rocky] Balboa" a long time ago and I hadn't seen Sly as often -- he was my film idol when I was a kid -- but every time I saw him he was like, "Hey kid, how you doing? Good to see you. What's going on? Call me anytime." Like, that's how he always was with me -- and always is with me -- so I felt comfortable reaching out to him and just saying "Hey, I want to talk to you about my show."

Because when I had bumped into him in the last year and a half at different events, or Golden Globes or things like that a.) he would always say how proud he was; and b.) we would just fall right back into the conversation that we had just as two guys who spent time together on a set, but he always reaffirmed: "Call me if you need anything."

I basically called with "Here's something that might be fun, and I'm sorry you and I aren't going to get at lot of screen time together, but I want you to know how much thins impacts my character." Because if you imagine that Sylvester Stallone is Kevin's movie idol, it's got to come from somewhere. Maybe that was his dad's movie idol. Maybe his dad goes through some pretty tough times and always goes back to that underdog story of the first "Rocky."

So I think seeing the parallels in all of that, I picked the phone up and called him and he was very engaged and receptive an excited and the emails went back and forth. He still remains one of the funniest, most terribly intelligent men that I've ever known.

And he's playing himself, right?

Sly does play himself. He plays Sylvester Stallone, the movie icon.

Did he know the show? Does he watch it?

Yeah. I don't know in great detail but I know when I seen him he's told me how proud he is of me. And I know Jennifer, his wife, and his daughters, are always like "Oh, my God. I love the show!"

I had an amazing time being with him on set 13 years ago and I'm just so thankful that I'll be sharing a call sheet with him again.

Did Sly ask you how Jack died?

No, he did not! [Laughs]

Are you relieved that people will get some information about Jack's death so they can stop coming up to you about that?

In the smallest way, yes -- only because I feel like people want to know and because I am the character and Dan [Fogelman] is writing the character. He and I are the ones that get hammered the most, but I also feel that there may not be the complete satisfaction just because of the event that happens -- the event of him dying. It's too soon in his life, it's too soon or too young in the character's that he impacts and I think it's something that no matter what, there's no way around it hurting. It's going to hurt.

What can you say about how Jack and Rebecca's relationship evolves in the Season 2 premiere?

We find them in that immediate fractured moment the day after the big argument and they have a long, uneven, unpaved road to walk to get back to being better. Some hurtful things were said, some things that you never want to bring into a relationship. The intensity of that fight is always going to cool off, but what doesn't go away is the hurt and the pain and what these people who have spent 20 years together experience.

Is that a big part of Jack's journey this season?

Very much so, but for all Jack's perceived perfection, I think what we're going to see a lot of this year is Jack's imperfection. Not that we're going to see Jack acting poorly or being poorly. We're just going to address the things that have impacted his life to where he puts on this amazing man quality, but really buries everything else because he does not want it anywhere near his family, anywhere near his wife, anywhere near his kids.

He's at the point before his death, he's an early-fifties man who's experienced life. I know at forty I've seen a thing or two, so I couldn't even imagine what he'd seen in his fifties and in the era that he was living as well.

At this stage of your career, what did the Emmy nomination mean to you?

There was a bit of validation to 22 years of work, of hard work. I feel that sometimes awards have a way to diminish the hard work of other people, just in entertainment, so there was a little bit of a mixed feeling on that. At the same time, it doesn't change a thing. I still approach the work the same, I show up every day, excited to be there.

And it's a humbling experience but also there are a lot of things that go into it. I'm only some makeup of the people that [work with]; I get to speak Dan's words, I get to look into Mandy [Moore's] eyes and be on the set with our crew. I'm a piece of the equation.

It was a shock that Mandy wasn't among the show's many Emmy nominees.

I was very upset. If I'm being kind with words, it's very upsetting. That's very difficult because I felt like her performance is in me and my performance is in her and what we do together is what and who Jack and Rebecca are.

And it's always upset me when I've seen other actor couples, on-screen couples, that one gets recognized and the other doesn't. Like when Ruth Negga gets recognized [for "Loving"] but Joel Edgerton doesn't. How do you separate the two? It's all part of the same, so it upsets me. But it's one of those things that doesn't really change the work. For me, it always goes back to the work.