Los Angeles (CNN) -- Michael Jackson's mother will be called back to testify by AEG Live as its last witness in their defense of Katherine Jackson's wrongful-death lawsuit on Monday, an AEG Live lawyer said Wednesday.
AEG Live lead attorney Marvin Putnam said he would question the 83-year-old Jackson family matriarch "about the absurdity of the damages" she wants the jury to award if they decide the concert promoter is liable in the pop icon's death.
A Jackson lawyer argued that AEG Live's "intent is to show the lawsuit's purpose is greed," while the judge suggested that any mother could be expected to say "there is no amount of money that would substitute for the loss of her son."
Putnam has frequently cited in interviews a "statement of damages" letter sent to him by a Jackson lawyer last year capping possible damages at $40 billion, but the judge ruled that he could not refer to it in court because it was not a sworn filing in the case.
Jackson lawyer Kevin Boyle pointed out that the lawsuit complaint only says that damages would be "according to proof at trial," based on testimony by several expert witnesses who have testified.
Katherine Jackson and grandchildren Prince, Paris and Blanket contend that AEG Live is liable in the singer's death because it negligently hired, retained or supervised Dr. Conrad Murray, who was convicted of involuntary manslaughter. AEG Live argues that Jackson chose and controlled Murray and that its executives had no way of knowing about the dangerous treatments he was giving him in his bedroom.
Jackson expert Arthur Erk -- a certified public accountant who has managed and audited the business affairs of many top artists -- testified that he was "reasonably certain" that Jackson would have earned at least $1.5 billion from touring, endorsements and sponsorships had he not died from a propofol overdose preparing for his comeback tour.
"It is very difficult to assess the value of the King of Pop," Jackson lawyer Deborah Chang told the judge Wednesday. "How do you even do that?"
The non-economic damages suffered because of Michael Jackson's death could be enormous considering "what happened to Paris Jackson," she said.
Jackson's 15-year-old daughter attempted suicide in June and remains in a treatment program.
The $40 billion estimate made last year was not a court filing but was a "best guess" before the expert reports were completed, Chang said.
Jackson lawyers seemed to welcome the prospect of AEG Live calling their client as their final witness, considering how jurors reacted when she was on the stand in July. Jurors leaned forward and paid close attention during her two days of testimony as the last witness in their case.
"Why are you here?" Jackson lawyer Brian Panish asked her.
"Because I want to know what really happened to my son," she said. "And that's why I am here."
Panish asked Jackson how it made her feel to be asked probing and personal questions about her family by AEG Live lawyer Marvin Putnam.
"It makes me feel real bad, because my son was a very good person," she said. "He loved everybody. He gave to charity. He was in the Guinness Book of World Records for giving to charity."
in July, she told jurors she filed the wrongful death lawsuit against AEG Live "because I want to know what really happened to my son."
If jurors decide that AEG Live is liable in Jackson's death, they could award damages based on the loss of the mother's and children's relationship with him and the amount of money he was unable to earn because his life was cut short.
After AEG Live rests its case -- which lawyers indicated would happen Monday -- the Jackson lawyers would have a chance to call several rebuttal witnesses. Closing arguments in the trial, which began in April, could be heard as soon as next week.