Butz Steps In For SPEED-THE-PLOW, Piven Back In LA

Over the past few weeks, the star had complained of "exhaustion" and "being tired," sources told The Post. The popular play's investors aren't buying it - and are discussing calling in their own doctor in to get a "second opinion," sources told the Post.

Witnesses have told The Post that Piven is a regular at the Lower East Side bar The Eldridge.

"He lives his life very much like the way his character on 'Entourage' does," said one source.

Investors are worried that without Piven - one of the play's main attractions, who had earned up to $15,000 a week - they might not be able to recoup their $3.5 million outlay, on which they figured they'd break even by next week. At yesterday's matinee, more than 300 ticketholders demanded a refund when they heard Piven was a no-show.

The Post revealed that box office has already handed out roughly $20,000 worth of refunds because of his absence.

Piven has temporarily been replaced by Tony-winner Norbert Leo Butz, 41, who spent yesterday studying the script.

Even more alarming is the Post's report that Piven previously had been showing up late to performances each night, barely making it to the Barrymore Theatre on West 47th Street before the curtain went up. Under union rules, he is required to sign in by 7:30 for an 8 p.m. curtain.

Daily Variety reached out to David Mamet, who wrote the showbiz satire and seemed less than convinced by Piven's departure. Mamet commented, "I talked to Jeremy on the phone and he told me that he discovered that he had a very high level of mercury," Mamet said. "So my understanding is that he is leaving show business to pursue a career as a thermometer."

Mamet indicated to Variety that despite Piven's exit, the show will go on. "The good news is that some really great actors will be helping out and stepping in, which to me is a sign of great heroism and friendship," said Mamet, who declined to name the replacement.

A spokeswoman for the actor said he wanted to continue in the role, but that doctors advised him he should end his run immediately.

Piven's spokeswoman commented to Variety that "the diagnosis came from a team of doctors headed by Dr. Carlon Colker, an internist and attending physician at Beth Israel Medical Center in New York and Greenwich Hospital in Connecticut, and also CEO and medical director of Peak Wellness".

Piven was scheduled to perform throughout the show's run, which is scheduled to run until Feb. 22nd.