Some celebrities blame vertigo for their absences, others chalk it up to simple “exhaustion.” But up until now, I doubt anyone has pleaded guilty to an overconsumption of sushi.

After missing several performances of Speed-the-Plow earlier this week (that’s the same play Madonna once starred in), Entourage star Jeremy Piven has abruptly left the Broadway production. A high level of mercury is apparently the reason for the Piven’s medical leave.

A twice-a-day sushi meal and a regular intake of Chinese herbs are believed to be the factors behind Jeremy’s illness. A high level of mercury can apparently lead to cause cardiac arrest, kidney failure, even psychiatric problems

After hearing skeptical comments about Jeremy’s excuse (playwright David Mamet joked that his Piven was “leaving show business to pursue a career as a thermometer”), the actor’s physician came to his defense. According to Dr. Carlon Colker, the 43-year-old had been feeling ill for some time. When Colker discovered that Piven had a mercury level “almost six times the upper limit of normal and allowable,” he warned the producers back on December 10.

Although Jeremy attempted to continue on, the actor eventually found himself hospitalized for three days after experiencing dizziness. That was when Piven was told to cancel his engagement altogether. “It was not his decision to step away from this play, it was mine. I think it was in the best interests of his health to do that,” Colker stated.

William H. Macy (a big Mamet collaborator) and Tony winner Norbert Leo Butz (Dirty Rotten Scoundrels) will both step in as the Bobby Gould character until the show’s Feb. 22 close.