This Is Us Stars Rave About Working with 'Icon' Sylvester Stallone — and Will We See a Mandy Moore & Chrissy Metz Duet?

The This Is Us cast has some surprises up their sleeves for season 2 — including a guest appearance from Sylvester Stallone and (maybe!) a possible Chrissy Metz/Mandy Moore duet?

“Just being reunited with Sly was amazing,” Mili Ventimiglia, 40, told PEOPLE of his Rocky Balboa costar at a cast Q&A event on Monday. “I mean, I had a great time not only working with him but also learning from him 13 years ago and then continuing to see him over the years. To pick up the phone and call one of the greatest icons of American cinema, and say, ‘Hey I think you may have fun coming and playing with us,’ and him being excited about it — it’s a great feeling.”

“He’s full of great advice and great satires,” Justin Hartley, 40, said about the superstar guest. “I just like his energy. Just being around him, it’s like, ‘Wow that guy is just the epitome of cool.’ ”

This Is Us earned five Emmy nominations this year, including outstanding drama series. And gathering from what the cast has said so far about Season 2, the series will continue with the drama, along with a little comedy, and singing!

Metz, who admitted that she has been working with a vocal coach, teased that she will definitely be showcasing her voice on the upcoming season.

“Because Kate is in the beginning stages of really finding her own and finding her voice so to speak, I didn’t want to be overworked and overpolished and be too technical, I still wanted performance.”

Does this mean we’re going to see the Chrissy/Mandy duet we’ve been waiting for?

Not quite, but definitely not out of the question. “I’m dreaming of it too,” Metz said.

FROM PEN: Chrissy Metz Talks About Her Weight Loss Journey Mirroring her ‘This Is Us’ Characters

In the spirit of thinking ahead to the new season, the cast also opened up about what advice they would give their characters if given the chance.

“I would tell Kevin that he should, every night before he goes to bed and every day before he goes to work, he should take five minutes, close his eyes and sort of center himself,” Hartley said.

For Sterling K. Brown’s character, Randall?

“Continue on the path that you’ve chosen when you left your job. You left your job so that you can actually enjoy life, so that you can smell the roses spend time with family connect with people. I think Randall is in a beautiful place to sort of release the pressure from himself to be perfect.”

But, Moore said it best.

“I want her to give me life advice,” she admitted. “She seems to have figured it all out. She’s wise.”

The second season of This Is Us premieres Sept. 26 at 9 p.m. ET on NBC.