Celebrity Rehab with Dr. Drew's fourth season has reportedly landed another participant.

Former Pointer Sisters singer Bonnie Pointer has joined the VH1 reality series, TMZ reported Friday, adding the 59-year-old will be treated for drug abuse.

Filming for Celebrity Rehab with Dr. Drew's fourth season was originally scheduled to begin on Tuesday, however that plan was reportedly scrapped because producers are having a hard time completing the celebrity cast.

Former A Shot at Love star Tila Tequila had committed to be a Celebrity Rehab cast member early last week, while Shauna Sand -- the ex-wife of reality retred Lorenzo Lamas -- also recently signed on to participate.

Former Laguna Beach star Jason Wahler was reportedly "very close" to an agreement to appear on the series, and Bone Thugs-N-Harmony rapper Bizzy Bone -- whose real name is Byron McCane -- also expressed interest in participating to receive treatment for marijuana and alcohol addiction.

While the VH1 reality series was also reportedly interested in casting actress/singer Liza Minnelli and Dutchess of York Sarah Ferguson, both have denied any involvement in the show.