Adam Scott felt shocked by Step Brothers casting, but why?

Adam Scott was surprised to land a part in Step Brothers.

The 53-year-old actor starred alongside Will Ferrell and John C. Reilly in Step Brothers, the 2008 comedy film directed by Adam McKay, but the actor admits that he never expected to be cast in the movie.

During an appearance on the Big Bro With Kid Cudi podcast, Adam explained: "Man, that was so exciting getting Step Brothers. Oh my god.

"I did not think I would get that part. And I think that's probably part of the reason I just went into the audition and just kinda went for it is because I was like, ‘There's no way.’"

Adam ultimately landed the part, after the original choice opted to withdraw from the project.

He said: "Someone had the role and then scheduling, they had to bail, so they had to cast it pretty quickly. So I got the part, and suddenly I was like, ‘Holy s***, I'm in this like Will Ferrell movie.’"

Adam relished the experience of working on Step Brothers, and he embraced the improvisation element of the shoot, too.

The Hollywood star shared: "John C. Reilly and Adam McKay [were] directing, it was a big deal. It was so fun. It was kind of terrifying because those guys ... they improvise a lot, and they're like the best improvisers in the world.

"And I didn't know what I was doing. I never really even been in a comedy before. I couldn't get auditions for like sitcoms and stuff. Like, I just had no kind of comedy credentials whatsoever."

Adam admits that he had to learn on the job while shooting Step Brothers.

The actor - who has also starred in movies such as The Aviator and Flower - said: "I was there, and so kind of had to learn to figure it out, figure out improvisation on the set of Step Brothers. So I equate it to, like, learning how to do the high jump at the Olympics. You know? It was crazy."

Adam recalled one particular scene that felt like a breakthrough moment in his own career.

He reflected: "I think it was like the dinner scene, and John Reilly and I started improvising about something — I don't think it's even in the movie, but we just started kind of going back and forth and kind of just flowing. And you're not even thinking about it, you're just going.

"And towards the end of the shoot, and I remember after cut, John C. Reilly was like, ‘Alright. That was fun. Like, wasn't that cool? That was fun. Right?’ I was like, ‘Yeah, man.’"