A trial will be held next month to determine whether Donald Sterling, who opposes his estranged wife's planned sale of the Los Angeles Clippers, was properly removed as an administrator for the family trust that owns the team.

An attorney for Shelly Sterling went to probate court Wednesday to request a trial to confirm that as sole trustee she can proceed with the $2 billion sale to former Microsoft CEO Steve Ballmer.

Her lawyer, Pierce O'Donnell, said three doctors have filed reports saying Donald Sterling lacks the mental capacity to be a trustee.

The trial, which was granted exceptionally quickly, will begin July 7 and last four days. The deadline for the sale is July 15, which is also the date the NBA Board of Governors is scheduled to vote on whether it will approve the sale.

Donald Sterling's lawyer, Bobby Samini, left the courthouse without comment after a clerk announced the trial schedule. Neither Sterling was present.

Commissioner Adam Silver, in an interview with ESPN Radio's "Mike & Mike" earlier Wednesday, said he remains confident the Clippers will be sold to Ballmer, but admitted he's worried that the process will be slowed down in the courts.

"It's like a house at closing: As long as [Shelly Sterling] can pass clear title to Steve Ballmer, then our process will continue," Silver said. "[Ballmer] will go through the usual vetting, but I don't anticipate any problems from our side. So really, it's just waiting on them. It will happen. And I think Donald ultimately knows that. He can jam up the works a little bit right now, but it's time for him to move on."

Donald Sterling said in a statement Tuesday that he's not just fighting for the Clippers but taking a stand against the NBA, which he called "a band of hypocrites and bullies" and "despicable monsters" who want "to take away our privacy rights and freedom of speech."

Donald Sterling is suing the league for $1 billion. The league has sought to ban him for life since racist remarks emerged in a recording in April.