Richard Senneff, the first witness in the civil trial, testified that he was initially unaware that the person lying in pajamas on a bed in the rented Los Angeles mansion was the world famous pop singer.
"The patient appeared to be chronically ill to me," Senneff testified, saying he could see Jackson's ribs. "He was very pale and underweight. I thought perhaps this was a hospice patient."
Jackson's personal physician, Dr. Conrad Murray, appeared "frantic" but never mentioned that the "Thriller" singer had taken the anesthetic propofol, Senneff said.
"He was pale, he was sweating, he was very busy," Senneff said of Murray, who was convicted in 2011 of the involuntary manslaughter of Jackson through an overdose of propofol, which is usually used in surgical settings.
Senneff, who gave similar testimony in Murray's 2011 criminal trial, was testifying on Tuesday on behalf of Jackson's mother and his three children.
Jackson's immediate family accuses AEG Live, who were promoting a series of London concerts by Jackson, of negligence in hiring Murray as the singer rehearsed for what would have been a career comeback after years out of the musical spotlight.
AEG Live maintains that Jackson kept his dependency on propofol secret from outsiders, and that a proposed contract with Murray was never fully executed.
Jackson, 50, was pronounced dead in a Los Angeles hospital on June 25, 2009, a day after a rehearsal and three weeks before the first concert was due to take place in London.
Katherine Jackson, 82, and the singer's two oldest children Prince and Paris, are also on the witness list later in the civil trial along with singers Diana Ross and Prince.
(Reporting By Jill Serjeant; Editing by Sandra Maler)