Joel Edgerton has admitted that he was medically advised not to take on the role in Warrior.
The actor teams up with Tom Hardy as mixed martial arts fighting brothers in the Gavin O'Connor directed movie.
But Edgerton was warned by doctors of the dangers of making a movie such as this - advice that he didn't take any notice of.
Speaking to The Age the actor said: "You take a few punches in the head, but that was kind of fun.
"I was actually advised by a doctor here in Sydney that it probably wouldn't be a good idea to do the movie.
"But I wasn't going to let that stop me. I'm not smart enough to take advice like that."
Warrior has proved to be one of the best movies of 2011 so far as Edgerton and Hardy put in great performances as the warring siblings.
And Edgerton will be back on the big screen later next month with his new movie The Thing, a prequel to the John Carpenter classic.
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