A real-life fish story has resulted in Jeremy Piven’s withdrawal from the current Broadway revival of the David Mamet comedy “Speed-the-Plow.”

Mr. Piven, the actor and “Entourage” star, left the production this week after having previously sought an early release from the play. Mr. Piven’s doctor said he should not continue to perform because he was suffering from elevated levels of mercury, which may have been the result of large amounts of fish in his diet.

On Thursday the producers of “Speed-the-Plow” said that Mr. Piven’s role as the Hollywood producer Bobby Gould would be taken over first by Norbert Leo Butz and then by William H. Macy. Mr. Butz is to play the role from Tuesday through Jan. 11, they said, and Mr. Macy is to take it on from Jan. 13 through Feb. 22, when the show is scheduled to close at the Ethel Barrymore Theater. Mr. Piven’s understudy, Jordan Lage, will continue to perform the role through Sunday.

Mr. Piven had been starring in “Speed-the-Plow,” with Raúl Esparza and Elisabeth Moss, since previews began on Oct. 3. Writing about Mr. Piven’s performance in the play, which opened on Oct. 23, Ben Brantley said in The New York Times, “Mr. Piven has the pivotal role, and he executes it with uncanny grace and intelligence.”