The Walk the Line actor plays Freddie Quell, a troubled, alcoholic World War II veteran recovering from post-traumatic stress disorder in the movie, but he struggled with anxiety and was convinced Hoffman and director Paul Thomas Anderson wanted to drop him from day one.
He tells Interview magazine, "You start a movie out and you read the script and you're so nervous and you just want to please your director so badly. But the first time I sat down with Paul and Phil and we went through a scene, I was convinced that they weren't going to hire me. I was convinced it was over. I was like, 'I can't believe it.'"
Phoenix beat James Franco to land the part, but he still felt like he was on probation even when cameras started rolling for real - and he was a wreck in scenes opposite Hoffman.
He says, "I got up at five o'clock in the morning and f**king studied through the processing scene on the boat because I knew we were going to rehearse that. I had to try and get it down. It literally felt like an audition. So we went in for the next rehearsal and I was like, 'I'm basically auditioning today', because the day before I was pretty sure Phil was like, 'This is not working' and Paul was going, 'I know. I don't know what to do.'
"No joke, because dude, for real, here's the thing: Phil is such a goddamn genius. So you're sitting there with this f**king genius, and he starts talking, and I'm like, 'I can't follow this guy. I'm not saying anything after him!' He can read a f**king grocery list and you're just like, 'Oh, so captivating...'
"It was incredible to be around him. So I was like, 'F**k, man! They ask me to do this movie, and we do rehearsal, and it's so bad and Paul is probably doubting it...' But yeah, then we just went back and rehearsed again, and that day I think we talked a bit more and maybe he was like, 'OK, I'll give him a shot.'"
However, Phoenix admits he thrives on his nerves whenever he starts challenging new film projects: "I'm almost 38. I've been acting for 30 years. But I still get nauseous the day before (shooting) and have weeks of incredible anxiety. They have to put f**king pads in my armpits because I sweat so much that it just drips down my wardrobe. For the first three weeks of shooting, I'm just sweating. It's pure anxiety, and I love it."