"I was ecstatic. I saw it as an amazing opportunity I never had before, really. To really be one of the tent-poles in a huge franchise picture," the 38-year-old actor told United Press International in a phone interview Tuesday.
The "Boardwalk Empire" cast member, who has earned acclaim for his work in the films "The Iceman," "Take Shelter," "The Runaways" and "Revolutionary Road" was recently seen in the Broadway production of "Grace."
In "Man of Steel," Shannon plays the military leader who disagrees with Superman's scientist father Jor-El, played by Russell Crowe, about how to give the denizens of their dying planet Krypton a future.
Written by David S. Goyer and directed by Zack Snyder, the Superman origin story stars Henry Cavill as Kal-El/Clark Kent/Superman, Amy Adams as reporter Lois Lane, Laurence Fishburne as newspaper editor Perry White, and Diane Lane and Kevin Costner as Clark's adoptive parents, Martha and Jonathan.
Asked if it was important to him that audiences see Zod not as a mustache-twirling villain, but as a man determined to save his people at any cost, even if it means destroying the Earth to re-build his dead planet's civilization on top of it, Shannon told UPI: "I think that was real important to David and Zack.
"I honestly didn't worry too much about how Zod was going to be perceived because I don't really think Zod worries too much about how he is perceived," the actor observed. "I don't think Zod worries about much of anything except trying to save his planet and his people."
So, how physically demanding was the role, which required Shannon to battle Crowe's and Cavill's characters, as well as various other foes?
"There was a lot of physical training involved and a lot of learning fight moves and choreography," Shannon explained. "I think what was most surprising for me was just how much teamwork there was. A lot of times, I'd show up and just be doing very interesting scenes. Two characters talking. I think one of the strengths of the movie, ultimately, is it's not just awesome spectacles and fight sequences to beat them all, but there are also some very thoughtful, complicated themes between very rich characters."
Rated PG-13, "Man of Steel" is in theaters now.