"(His lawyers) felt the trial was going well enough that he did not need to testify," she said. "Jerry wanted to testify, but they felt he didn't need to testify."
Williams called Markle a "selfless friend" in a statement posted on Twitter Sunday night.
The tournament will tip off on Wednesday at T-Mobile Arena in Las Vegas.
Ahead of Sunday's NBA All-Star Game, Mitchell dismissed James' comments made at the Jazz's expense when he left two Utah players until the end of the All-Star Game draft.