*While Chris Sullivan spent a decade working in Chicago theater before his more recent, high-profile roles in the hit TV series “This Is Us” and now “Guardians of the Galaxy, Vol. 2” (opening Friday), the actor sees a universal similarity to all acting projects.

“One thing I’ve learned is whether it’s theater or film or television, the only thing that changes is the budget,” said Sullivan, calling from New York, where he was heading to rehearsal for a concert gig at Carnegie Hall. “Whether it’s a $50,000 independent film or something like ‘Guardians’ — where I don’t even know what the budget is! — the process is the same, whether it’s the writing, acting, directing, rehearsing or the structure of shooting a scene. It’s always fascinated me that the process remains the same.

“But, like we saw on ‘Guardians,’ the sets [headquartered in Atlanta] are a LOT bigger,” said the actor, whose new character Taserface is one of the marauding Ravagers working for Yondu (Michael Rooker). “We actually had to move the set for the Ravagers to the convention center in Atlanta — because there wasn’t anything else big enough to facilitate it.”

Among Sullivan’s favorite Chicago stage experiences were plays he did with The Hypocrites — and working with artistic director Sean Graney. Sullivan recalled Graney once telling him that even if he were to show up eating a sandwich for an audition, Graney would cast him — no matter what. “So, when I went to audition for ‘The Hairy Ape,’ I walked in eating a 6-inch Subway sandwich,” said Sullivan with a laugh. “But, it worked out. I got the part!”

While Sullivan claimed he was not that big a fan of comic books or superheroes as a kid, he did “feel like a total 12-year-old,” while filming the new “Guardians” flick. “It was a total blast every single day.” One particularly fun day was when Sylvester Stallone showed up to play the role of Stakar Ogord, a leader of the Ravagers.

“Not only did my jaw drop, but everyone on set’s jaw dropped,” said Sullivan. “They keep a lot of stuff on these films as closely guarded secrets. So, no one knew Stallone was coming, until he showed up. That was one of many things working on this project that totally blew my mind.”

Chris Sullivan as Taserface in "Guardians of the Galaxy, Vol. 2" | Marvel Studios

Chris Sullivan as Taserface in “Guardians of the Galaxy, Vol. 2” | Marvel Studios

As for his now more infrequent return trips to Chicago, Sullivan ticked off his favorite places to go and things to do: “I always try to make it to iO [Theatre], where I did my improv training. I always try to catch a Hypocrites show. … Even though I’m not a baseball expert or one of the Cubs’ largest fans, there’s something about going to Wrigley Field — it’s like walking into a church. In general, when I’m in Chicago I try to make a point of trying to connect with the music, the comedy and the theater scenes.”

The success of NBC’s “This Is Us,” on which he plays Kate’s fiance Toby, “is kind of mind-blowing” for Sullivan. “It’s a miracle when any film or television show even gets made — let alone become successful. To me, I think the show is a success because when the writers are telling the truth about contemporary life and people, the audience enjoys it and relates to the stories we’re telling.”

All that said, Sullivan did leave me with one final note: He’s loved to return to Chicago to do another play. “If there’s anyone out there listening, tell them there’s nothing more I would enjoy!”