The actor, 44, denied the allegations, and now, Hewitt, 22, is gathering witnesses to face him in court.
The Blast was the first to report Witherspoon's participation in the trial.
According to the court documents obtained by Radar, Hewitt has listed Witherspoon, 43, as a witness. She also listed Phillippe’s ex-fiancee, Paulina Slagter.
The Big Little Lies actress is scheduled to appear in court for an hour during the trial, which is slated to begin on October 15.
Last month, Phillippe pleaded with the judge to not allow Witherspoon to be deposed by Hewitt.
Phillippe — who was married to Witherspoon from 1999 to 2007, and has two children with her — said he believed her testimony is irrelevant to the case.
“Although divorced, they maintain a pleasant relationship with each other and their child. The nature of their marriage and its termination, as well as their ongoing relationship could only be used in this trial for improper purposes,” argued Phillippe’s lawyer.
But Phillippe and his team lost the battle, and Witherspoon will be present in court.