Asked if he thought Joaquin Phoenix (who went on to play the Johnny Cash role in the movie - which scored him a best actor nomination at the Oscars and a win at the Grammys) did a great job, Russ was generous with his praise of the actor.
“Oh, he did. I know from personal experience that he’s one of the greatest actors out there, so the fact he did an incredible job is absolutely no surprise to me,” Russell said of Joaquin.
“But from the very first notes … when the soundtrack starts, the knife jabs into the heart began … oh god, not only did I want to do the movie, but this is the exact version of the movie I wanted to do.”
Russell also got candid with the hosts around why he rejected the role or Aragon in Lord of the Rings - a part which came with a 10 per cent stake in the movie franchise - because he didn't think director Peter Jackson really wanted him in the part.
"It was 10 per cent of the gross [of the movie franchise]," he revealed of the paycheque that could have been his.
Speaking of a phone conversation he had with Peter Jackson, Russell said he "got the sense he really wasn't that interested" in him being in it, but would accept it if he had to.
Kiwi actor Russell was at the height of his Gladiator fame, which made the actor hot property.
"At the time it was the right decision for me," Russell said.
LISTEN THE THE FULL INTERVIEW BELOW