With “The Comedians,” Billy Crystal returns to TV for the first time as a series regular since “Soap” went off the air in 1981 — the same year his “Comedians” co-star Josh Gad was born.

The 33-year age gap between Crystal, 67, and Gad, 34, is the main point of hilarity in FX’s new half-hour comedy, which premieres Thursday.

“It’s a show, at its core, about the generational disconnect of two comedians coming from completely different eras being forced to understand each other,” Gad told Variety. “Being forced to connect and bridge the gap between that schism where my generation sort of comes from a place of irony and Billy’s generation comes from a pure place of comedy, and so when you mix those things together, what happens?”

What happens is the formation of a dynamic duo, displayed by laugh-out-loud chemistry and larger-than-life sketches in the series’ show-within-a-show format, formed by two unlikely suspects.

“We put together this really terrific, formidable producer group and then we said, ‘Now who’s going to be the other guy?'” Crystal explained of the casting process for his partner and crime, jabbing, “And once Jack Black said no…”

Cracking up, Gad interrupted Crystal: “Jonah Hill wasn’t available.”

Joking aside, Crystal and Gad, sitting side-by-side chatting with Variety, could not speak more highly of each other.

“He’s so schooled,” Crystal raved of Gad, who scored the part after just one quick meeting with exec producers Larry Charles, Ben Wexler and Matt Nix, after Crystal watched him perform a “Book of Mormon” number when he was being honored at the Geffen Theater. “He’s such an old pro in so many ways that we just fit together like a glove. Not just the sketches — that’s bonus stuff. We have an amazing amount of fun on and off and we know where the edges are and the seams are to play together.”

Gad, clearly still pinching himself over his role of a lifetime, added: “Literally, you’re talking about my idol. I was like, ‘Are you kidding me?’ I almost fainted when I got that call.”

Though the pair is overly fond of each other offscreen, they’re tasked with displaying the exact opposite sentiment onscreen.

“What was interesting is when we started developing the show, the decision was, well who do we play? Do we play ourselves or do we play fictitious characters?” Crystal explained. “So we said, no, let’s jump in, but each of us has to be willing to take some shots at our personas. We started right off with, ‘When I got the call, nobody was more excited than my grandparents,'” he recalled, alluding to one of Gad’s lines in the show, which was one of many spur-of-the-moment gems, resulting in the duo’s self-deprecation and “real portrayal, even though it’s stretched a little bit.”

Laughing, as he reminisces on certain scenes, Gad added, “That’s what makes the show so unbelievably special and, I think, unique. If you don’t have a thick skin and you’re unwilling to make fun of yourself, it’s an unpleasant place to go, and having a sparring partner like Billy Crystal, I don’t know if I could do it otherwise.”

Though some of their great moments came about unplanned, the creative team worked hard to create a certain tone for the series.

“There’s a great deal of it that’s improv, but we wrote really good scripts,” Crystal said. “We spent the summer really working hard with the writers to school them in us. We were really careful in what we were doing and wouldn’t settle. I think that was a real key in setting the tone for what the season would become.”

Even with his legendary comic career, Crystal is proud of his latest project. It provides him, he says, with the perfect work at this stage in his life. “What I saw was the potential to do what I grew up doing and what I love doing — I could be myself, I can play characters, we can do a live show.”

He admitted that the show is a rewarding challenge for him and graciously gives kudos to his much-younger castmate.

“The show has a great shooting pace to it. We do a lot. One day we shot 11 pages in four hours. I do 11 pages in one week in a movie,” Crystal said. “Larry [Charles] has an amazing kind of ear for minutiae and little moments. All these little gems come out at the end. It’s a relaxed tough schedule.”

He’s even learning from Gad, who grew up studying his work. (Gad recalled, “I always tell Billy this story about watching ‘Comic Relief V’ — why my parents let me watch that at such a young age, I’ll never understand — but I watched ‘Comic Relief V,’ and I remember looking at Billy and being like, this man is exactly who I want to grow up to be.”)

“Josh commits,” Crystal said. “When he’s inside an improv, when he’s inside himself, he never goes away. I’ll crack up and laugh. He never loses it. He never goes away. There was this one scene, and I know he’s great and I’m ruining it, but I can’t help it. I enjoy him. Josh is very smart, he’s extremely intelligent and a very intuitive actor where you can throw anything at him and it comes right back. I am amazed in some ways at his instant concentration. As soon as they go ‘action,’ he’s ready.”

Gad admits that everything and anything his co-star does makes him laugh so he usually “explodes” right when the director calls “cut,” but still, Crystal throws in one more compliment: “And to find someone this young so attractive,” he started to say. Finishing his idol’s sentence, Gad humbly responds, “Sure, I could lose a couple of pounds, but can’t we all?”