The 42-year-old actor plays the role of fighter Charlie Kenton in the new movie but said his biggest stepping stone moment was over 10 years ago when he had to perform in front of a huge crowd.
He said to UK newspaper Daily Mirror: 'The greatest for me - and I'd never been more scared - was singing the national anthem at an Australia vs New Zealand rugby game in front of 100,000 people at the Melbourne Cricket Ground on July 26, 1997.
'I'll never forget it. I had a panic attack the night before because I was an actor and I didn't know why I was singing the national anthem in the first place.
'Then when I went on, 30,000 New Zealanders who'd flown over were just booing me. I instantly felt this outrage that they would boo on Australian home ground and became like Henry V. Then it went well.'