Dr. Conrad Murray arrives at the Armstrong Medical Clinic in Houston
Dr. Conrad Murray arrives at the Armstrong Medical Clinic in Houston November 23, 2009. The cardiologist plans to resume work for the first time since the death of pop star Michael Jackson. REUTERS

Michael Jackson's dermatologist will not testify in the trial of Dr. Conrad Murray, a judge ruled on Monday, in a blow to defense plans to portray the singer as a drug addict who may have given himself the substance that caused his death.

Los Angeles Superior Court Judge Michael Pastor also barred witnesses in the case from testifying about Jackson's 2005 trial and acquittal on child molestation charges.

Murray's involuntary manslaughter trial is slated to begin next month over the Thriller singer's June 25, 2009, death from what authorities said was an overdose of the powerful anesthetic propofol and other drugs.

Murray has admitted giving Jackson, 50, propofol as a sleep aid, even though it is normally used in a hospital setting. Murray's lawyers have suggested the pop star could have given himself a further dose when his physician was out of the room.

In court papers, Murray's attorneys said they wanted to call Jackson's longtime dermatologist, Dr. Arnold Klein, to the witness stand.

The papers said Klein gave frequent injections of the painkiller Demerol to Jackson for no valid medical purpose and that Jackson became physiologically and psychologically dependent on Demerol.

I do not think it is relevant, Pastor ruled on Monday. Pastor also barred the testimony of five other doctors, but said he would allow defense attorneys to call two other physicians -- Allen Metzger and David Adams.

Murray was hired as the singer prepared for a series of comeback concerts which had been scheduled to begin in London in July 2009.

The defense contends that Adams told police Jackson was so familiar with propofol that he called it milk.

Metzger had treated Jackson for two decades, and as recently as two months before the singer's death, Jackson had asked Metzger for intravenous sleep medicine, the court papers from defense attorneys said.

Prosecutors told the judge on Monday that Metzger had turned down Jackson's request.

Pastor on Monday also refused a request by the defense to bring up a 2003 raid of the singer's Neverland Ranch in California, in which defense attorneys said propofol and Demerol were found.

Murray's team had said in court papers that they did not plan to refer to the child molestation charges on which Jackson was later acquitted.

Pastor said testimony about the Neverland raid would be irrelevant and that it proves absolutely nothing involving Jackson's 2009 death.

Murray has pleaded not guilty to involuntary manslaughter. He faces up to four years in prison if convicted.

Jury selection in the case is due to begin on September 8 and opening arguments are set for September 27.