Amber Heard's team will not call Johnny Depp to the stand, a source close to Ms Heard said, a strategic U-turn in the last days of the high-profile trial.
Ms Heard's team had planned to call Mr Depp for more questioning on Monday, but changed course without explanation at midday.
Mr Depp, 58, sued his ex-wife for $50m (£40m) for a column she wrote in which she claimed to be a victim of domestic abuse. Ms Heard, 36, has countersued.
The case is expected to wrap this week.
British supermodel Kate Moss, a former girlfriend of Mr Depp, is among witnesses expected to take the stand in the remaining days of the defamation trial.
On Monday, the court in Fairfax, Virginia, heard from several witnesses called by Ms Heard's team, including psychologist David Spiegel.
Dr Spiegel testified that Mr Depp "has behaviours that are consistent with someone that both has substance use disorder as well as behaviours of someone who is a perpetrator of intimate partner violence".
About 40-60% of intimate partner violence is committed under the influence of alcohol or substance use disorders, Dr Spiegel told jurors.
Mr Depp's lawyers sought to undermine this testimony on cross-examination, highlighting that Dr Spiegel had reached his conclusions without any direct contact with Mr Depp.
Also on Monday, a hand surgeon testified it was unlikely that Mr Depp's finger was cut during a fight with Ms Heard in Australia in the way that he has described.
Mr Depp has said the tip of his middle finger was severed when Ms Heard threw a vodka bottle at him.
The jury saw graphic images of Mr Depp's injured finger as Dr Richard Moore said that the damage was more consistent with being pinched by a closing door.
Dr Moore did not physically examine Mr Depp at the time of the injury.
Ms Heard's team is expected to rest its case early this week before Mr Depp's team takes its final chance to sway the jury.
The testimony from the two medical doctors on Monday was just the latest in a long line of competing expert testimony. One psychologist, called by Mr Depp's team, testified that Ms Heard suffers from two personality disorders.
Another, called by Ms Heard's team, rejected this finding and said instead that Ms Heard had post-traumatic stress disorder.
Ms Heard and Mr Depp have each testified in the weeks-long battle, offering starkly different accounts of their brief, tempestuous marriage.
Ms Heard claimed Mr Depp was prone to alcohol and drug binges, easily triggered by feelings of jealousy and often consumed by violent rages.
Mr Depp, in turn, alleged he was the victim of Ms Heard's volatile moods, telling jurors he routinely endured her verbal, emotional and physical abuse.