Is Charlie Sheen back to his bad behavior of the past? Rumors of drug use and a relapse have surfaced after the actor has reportedly been a no-show for several days of work on his show Anger Management. His absences have reportedly infuriated the cast so much that they are threatening to quit if the no-shows continue. FX is eager for Sheen to stay sober and not fall back into his old drug addiction because Anger Management is expected to generate between $350-500 million in revenue if it completes its 100-episode order, which is two-thirds done right now.

Sheen’s absences from work have forced production to use stand-ins for him in certain scenes and delayed taping by several days. But Sheen’s publicist, Jeff Ballard, said the troubled actor is not using drugs and will return to work tomorrow. "We did not shoot last week because another member of the cast was sick,” he said to Hollywood Reporter. "Charlie is always ready, willing and able to shoot Anger Management and looks forward to returning on Monday."

Charlie Sheen Charlie Sheen used the N-word during a drunken rant at a porn star.

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Of course, Sheen has famously struggled with drug use and was fired from Two and a Half Men due to his erratic behavior. Last year, he fired cast member Selma Blair via text message after she reportedly questioned his work ethic, calling her a “c*nt” in the text exchange. Sheen also made a bizarre appearance on The Tonight Show with Jay Leno last February that made many question if his drug addiction was creeping back up.

Charlie Sheen and Brett Rossi Charlie Sheen is engaged for the fourth time, this time to adult film actress Brett Rossi

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Although the ratings for Anger Management are far from what they were when the show first premiered, it has still done well in recent months. Sources say the show could generate as much as $800 million in revenue if it reaches the 150 episode mark, once network license fees, international sales and syndication revenue are included. Because of Sheen’s global recognition, Anger Management is expected to generate around $1 million per episode overseas.

It’s been an eventful few weeks for Sheen. Last month, he got engaged to adult film actress Brett Rossi. He said he is even considering having kids with her, but isn’t planning on it for the foreseeable future. “I’m having way too much fun with her right now,” he said. “So much fun it should be illegal.” Sheen also said he will not make Rossi sign a prenup because “prenups poison marriage.” He will instead get her to sign a one-line contract that simply says “you keep your s*** and I’ll keep mine.”