Joaquin Phoenix was so nervous about promoting new movie Walk the Line on the OPRAH WINFREY SHOW, the talk show queen had to coax him onto the stage.

The actor - who plays Johnny Cash in the new biopic - tried to back out of the chat, because he feared vomitting on TV.

Oprah, who is celebrating the 20th anniversary of the show, tells US TV show Extra, "Nervous is not the word. He was a wreck. I've never seen nervous like that before.

"I had to go in the green room, and literally said to him, 'You don't have to put yourself through this.' He said, 'I think I'm going to throw up.'"