Los Angeles, Aug. 26 -- Shooting for 'The Smashing Machine' was quite challenging for Dwayne Johnson.

In an interview with Vanity Fair, Dwayne Johnson revealed he spent three to four hours putting on prosthetics each day, as per Variety.

"It was very real. I had not experienced that in a very, very, very long time, where I was really scared and thinking, 'I don't know if I can do this. Can I do this?'" Johnson said.

"I realized that maybe these opportunities weren't coming my way because I was too scared to explore this stuff... I was so hungry for an opportunity to do something raw and gritty and rip myself open. And all of a sudden, 'Smashing Machine' comes along," he added.

In the film, Dwayne will be seen as two-time UFC heavyweig...