Piven said he left the play mid-run because he was suffering from mercury poisoning, due to eating too much fish, as well as Epstein-Barr disease. The show's producers, however, filed a grievance against Piven, claiming he dropped out of the stage drama because he was bored and handled his departure unprofessionally.
An arbitrator ruled in Piven's favor last month.
Piven said on Tuesday night's "Late Show with David Letterman" that he decided to leave the play after he was hospitalized and a doctor told him he would risk a heart attack if he went back.
"And you have a decision at that moment to either take his advice or you say, 'Screw you, I'm gonna jump back on that stage.' I took his advice, and then this kind of turned into, 'I ate a bad piece of yellowtail and bolted,' you know? ... I'm so sorry that it happened because I wanted to continue the run. It was the time of my life."
Asked if he plans to return to Broadway some day, Piven told Letterman he "would love to."
"I've grown up on the stage and I come from a theater family, so, you know, this is our livelihood," he added. "It's our lives, and I can't wait to get back on the stage and I feel stronger than ever."
The Emmy Award-winning actor can now be seen on TV's "Entourage."