Dwayne Johnson has revealed what drew him to take on the role of Mark Kerr in the upcoming film The Smashing Machine.

Johnson will portray Kerr, a two-time UFC Heavyweight Tournament Champion and former PRIDE FC Heavyweight Champion, who struggled with life outside the sport. Behind the accolades, his career was derailed by a long battle with addiction to painkillers and narcotics.

Johnson will also star alongside Oleksandr Usyk, who will also feature as the Ukrainian kickboxer Igor Vovchanchyn. Johnson is a longtime fan of combat sports, having awarded Jorge Masvidal the inaugural BMF Title at UFC 244. He even once considered competing in MMA himself. Johnson wanted to put himself out of his comfort zone with this new role.

“I had been wanting for years now to chase the challenge and be inspired by the challenge. I love making the bigger blockbuster movies. They’re a lot of fun. They’re hard as shit to make, and a lot of people enjoy them, hopefully, knock on wood, around the world. But I wanted more. I wanted a challenge, and I just wanted the opportunity to disappear into something and disappear into a part and a role that would really challenge me in ways that I’ve never been challenged before,” Johnson said