Leno is expected to say the accuser's family badgered him for financial help. Other witnesses may include comic Chris Tucker and a Celebrity Justice reporter.
Tucker, who like Jackson befriended the boy while he was battling cancer, is expected to testify about spending time with the family. They took several trips together, including one to visit Jackson in Miami in February 2003.
Defense attorneys say the boy's family exploited his battle with cancer to target Jay Leno and other celebrities, including Jackson, in attempts to get money. The talk show host is expected to testify about a phone call the defense says he received from Jackson's accuser.
CBS News Correspondent Sandra Hughes reports Leno may hold a very important key to Jackson's defense. Hughes reports Leno is expected to testify that Jackson's accuser tried to become part of Leno's life, too, at his mother's behest. The boy denied ever even calling Leno when he testified at the beginning of this trial.
Hughes reports that if Leno comes into the courtroom and says that in fact he did have a conversation with the alleged victim, that could be pivotal.
Monday, defense attorneys tried to portray the mother of Jackson's accuser as a welfare cheat who exploited her son's cancer for money, and lived lavishly at Jackson's expense at a time she claims she was being held captive.
The defense called witnesses to show an alleged history of money schemes and her angry rejection of anyone who sought to help her with anything but cash.
The mother's former sister-in-law said her efforts to hold blood drives when the accuser was ill with cancer were dismissed by the mother, who called her and used profanity to denounce her.
"She told me that she didn't need my (expletive) blood, that she needed money," said the former sister-in-law, bursting into tears.
The defense, seeking to show Jackson was another target of such schemes, called a flurry of witnesses as it neared the end of its case. Jackson's attorneys were expected to call comedian Jay Leno on Tuesday, with the possibility they would rest by the end of the day.
Jackson, 46, is accused of molesting a 13-year-old boy in February or March 2003, plying him with alcohol and conspiring to hold the family captive to get them to rebut an embarrassing documentary.
The boy appeared in the documentary with Jackson, who said he let children sleep in his bed, but that it was non-sexual.
The defense also called a welfare worker who said the mother did not disclose on a welfare application that her family just 10 days earlier had received funds from a $152,000 lawsuit settlement.
Also, an accountant showed the family racked up $7,000 in shopping, dining and other expenses paid by Jackson during a week of their alleged captivity.