Originally Published: 23 MAY 22 14:08 ET

Updated: 24 MAY 22 04:41 ET

By Sonia Moghe, CNN

(CNN) -- Kate Moss, who dated Johnny Depp in the 1990s, is expected to be called to testify as a rebuttal witness by his legal team in the ongoing trial between Depp and his ex-wife Amber Heard, a source close to Depp tells CNN.

A source close to Depp confirmed that Moss and Depp remain close to this day.

Depp has sued Heard for $50 million alleging that a 2018 op-ed she wrote in the Washington Post defamed him, alleging the piece -- which did not mention him by name -- falsely painted him as an abuser.

Heard has countersued Depp for $100 million, saying statements his attorney made calling her abuse claims a "hoax" were defamatory.

Heard has testified on stand that she immediately thought about rumors related to Moss at the time Heard and her sister were in an alleged altercation with Depp.

"He swung at Whitney, and I'd heard a rumor, a vague rumor, about that," Heard testified on May 17.

In a 1998 Rolling Stone article, Depp is quoted as saying that, in conversations with author Hunter S. Thompson, "I was with Kate, and I think he went straight for the romance jugular, s* like whether I beat her enough. I probably told him, 'Yeah, she gets a severe beating.'"

Depp's team had no comment on the 1998 Rolling Stone quote.

Monday's testimony

During trial proceedings on Monday, Heard's team presented multiple expert witnesses, including two physicians.

Dr. Richard Moore, an orthopedic surgeon who specializes in hand surgeries, testified as an expert that the injuries Depp sustained to his finger after an incident in Australia were not consistent with his allegation that Heard slammed his hand with a glass vodka bottle.

Dr. David Spiegel, a psychiatrist who is an expert in intimate partner violence, testified that he believes Depp showed behaviors that are consistent with both someone who has a substance use disorder as well as consistent behaviors of someone who is a perpetrator of intimate partner violence. Neither Moore nor Spiegel have ever examined or spoken with Depp. Both reviewed medical records and testimony associated with the case.

Entertainment industry expert Kathryn Arnold also testified about her analysis of Depp and Heard's respective careers.

Arnold testified that she believes Heard's op-ed did not have much of an impact on Depp's career.

"Very little," Arnold testified. "Hardly anybody even knew the op-ed existed before he filed suit. If anybody that I know but certainly not Disney."

Arnold believes that Heard, on the other hand, has lost up to $50 million in possible earnings over the next five years due to Depp's attorney's statements calling Heard's claims a hoax.

Attorneys for both sides are expected to give closing statements in the case on Friday.