Chris Pratt, the American actor now considered one of the most in-demand star in Hollywood, has revealed that he initially turned down the opportunity to audition for Guardians of the Galaxy - Marvel's megahit that is likely to spawn a billion dollar franchise.

Guardians of the GalaxyGuardians of the Galaxy's lead man, Chris Pratt

Pratt initially passed on the lead in Guardians, fearing it would go the same way as his failed attempt to star in G.I Joe a couple of years earlier. 

"When Guardians of the Galaxy was pitched to me, I said, 'I don't think so.' I just didn't picture myself getting the role," Pratt told Esquire. "I didn't want to go and embarrass myself like I did when I auditioned for G.I. Joe a couple of years previously. I went in there, and halfway through I saw the director's eyes just glaze over. It made sense - I was a little heavy and out of shape. I was not gonna play someone from G.I. Joe. I did not look like a G.I. Joe action figure come to life."

More: Guardians of the Galaxy can go anywhere from here

After eventually accepting the role, Pratt famously underwent an intense workout schedule to get into shape for the lead in Guardians.

Guardians of the GalaxyGuardians of the Galaxy is great fun

"I can do 40-inch box jumps now. Action-hero physical stuff," he says. "Jumping that high feels really good. You see a giant hillside, and you think, I wanna get up that. You see a building, you think, I could climb that. When you get in shape, the world around you becomes things you wanna jump on and climb up."

As well as taking over $225 million at the box-office, Guardians of the Galaxy is also one of the best reviewed movies of the year.

More: read our review of Guardians of the Galaxy

"Not since Han Solo and Chewbacca hit the galaxy has there been as much raucous energy and sheer fun as in this blast of a sci-fi fantasy involving a daredevil adventurer and a mysterious orb," said Louise Keller of Urban Cinefile.

Watch the Guardians of the Galaxy featurette: