In emails obtained by the Los Angeles Times, AEG promoter Randy Phillips and AEG President Tim Leiweke discussed Jackson's unstable state in the weeks before the shows.
Phillips wrote in one email before a 2009 press conference announcing the concerts: "MJ is locked in his room drunk and despondent... I [am] trying to sober him up."
He went on to describe Jackson as "an emotionally paralysed mess," who was "scared to death" of facing the press and needed his manager to dress him.
Jackson would later die before the beginning of the live run due to an overdose of the drug Propofol.
The emails are part of a lawsuit between AEG and an insurance company hired for the tour, which is suing AEG in order to void a $17.5 million (£11m) claim.