MMA legend Ryan Bader makes his acting debut in The Smashing Machine - and it didn't take him long to realize he was in uncharted territory after filming with costar Emily Blunt. "We have a scene where she runs up and she's bawling," Bader, 42, exclusively told Us Weekly. "I'm holding her and this and that. They're like, 'All right, cut!' [Director Benny Safdie] was like, 'That was great, we'll do another one.' She stops crying. We're talking. We go back and she's just absolutely bawling again. I'm like, 'How does that happen?'" He added, "They were maybe going to have me cry. I was like, 'You guys got any bear spray to spray me with so we can get some tears out?'" Bader, a former Bellator World Heavyweight Champion and UFC fighter, plays MMA pioneer Mark Coleman in The Smashing Machine, which stars Dwayne Johnson as legendary MMA star Mark Kerr. Dwayne 'The Rock' Johnson Debuts Weight Loss Transformation for New Movie Together, Coleman and Kerr helped bring relevance and popularity to the UFC in its early days. Blunt, 42, plays Kerr's then-girlfriend, Dawn Staples. "We'd be sitting around [on set], and she'd be asking questions for hours," Bader said of Blunt's preparation. "The first time I met [Blunt and Johnson] was on a camera test and she came in. I'm nobody on set and she came and tapped me on the shoulder, gave me a big hug and was like, 'We're so grateful to have you here. Somebody who knows what they're doing on the MMA side of this.'" He continued about Blunt, "Every time we're on set, she's asking questions. But she was really getting into the character and what it would be like in 1999 in an MMA community. She was amazing." Bader also gushed about Johnson, 53, who he said "did his homework" when it came to embodying his demanding role. "He walked like Mark Kerr, he talked like Mark Kerr," Bader said. "He had his mannerisms, his soft voice. Before one scene in the movie, I walked into a locker room and he's sitting there. You know, everybody has their own way of preparing and getting into the role before a scene. He's in the locker room, gloved up, about to walk out. I walk in and he's just dead behind the eyes." Dwayne 'The Rock' Johnson's Body Transformation From WWE to Weight Loss He continued, "He's in his own head. Thousand-yard stare. I'm like, 'This feels real. This man feels like he's about to go fight. I got the chills because I've been there 43 different times. It's a very lonely place when you're about to walk out in front of fans in your underwear and go fight another trained human in a cage." Bader credited The Smashing Machine director Safdie, 39 - who's known for films like Uncut Gems and Good Time - with wanting to get things right. "Ben is all about realism, and this movie is so real. You feel it," Bader said. "Not only does the public feel it, but true MMA fighters go, 'Wow, all the little details are in there.'" The Smashing Machine is in theaters now.