The “Rookie” actor is featured in the new DC Studios extravaganza as Guy Gardner, one of the comic book characters who is elected to a position of intergalactic law enforcer known as a Green Lantern (yes – like the Green Lantern that Ryan Reynolds portrayed in the 2011 film). In the new “Superman” movie, just as in the pages of the comics, Guy rocks a severe bowl cut, complete with a mop of blondish bangs.

Reminding us that the hairstyle is “canon” to the original comics, Fillion told CNN, “I don’t think you can do a Guy Gardner without doing the hair. I think it would be a disservice.”

Adding that the look is “integral to the character,” Fillion pointed out that it even may clue viewers in to Gardner’s specific brand of bravado: “If you see a guy walking down the street with a bowl cut, that guy clearly doesn’t give a damn what you think about him. And that’s Guy Gardner.”

Indeed, Fillion’s Gardner is one of the many characters who provides brashness and comic levity to “Superman” – somehow he gets by throughout the entire film with only Lois Lane (Rachel Brosnahan) making one (much-needed) crack about his coif.

“Flying is so fun to watch, it’s fun to do, but the harnesses that you have to wear, they’re not built for comfort,” he shared. “They’re claustrophobic, they’re very constricting, they’re uncomfortable. I had a fist-sized purple bruise on my kidney from one.”

He added that the physical discomfort notwithstanding, he considers himself to be “very very picky about flight in film, so it was extremely important to me to get it right. That was a challenge.”

Fillion has worked repeatedly with “Superman” director James Gunn, ever since starring in Gunn’s gross-out horror comedy “Slither” in 2006.

Next year, Fillion will be reprise the role of Guy Gardner in a DC-based TV series titled “Lanterns,” costarring Kyle Chandler and Aaron Pierre and co-executive produced by Gunn.