Shelly Sterling is trying to sell the Clippers, while Donald Sterling is suing the NBA. (Andrew D. Bernstein/NBAE/Getty Images)

Disgraced Clippers owner Donald Sterling will file a lawsuit against the NBA seeking $1 billion in damages, according to his lawyer.

NBC News originally broke the story and Sterling's attorney, Max Blecher, later confirmed the report to Yahoo! Sports and ESPN.com, adding that the charges of the lawsuit include an invasion of Sterling's constitutional rights, violation of anti-trust laws and breach of fiduciary duty associated with the NBA's lifetime ban and termination charges.

Blecher also clarified that this lawsuit has nothing to do with the pending sale of the Clippers, though he told Yahoo! Sports that separate action regarding the sale was being considered.

This development comes on the heels of news that Sterling had recently been diagnosed with Alzheimer's disease. Sterling was reportedly diagnosed by doctors earlier this month and on Thursday it was reported that Sterling had been declared "mentally incapacitated" -- a determination that removed him from power of the Sterling Family Trust and, by extension, the Clippers. That left Shelly Sterling as the sole trustee of the family's trust, a status which fully empowered her to sign a $2 billion agreement to sell the Clippers to former Microsoft CEO Steve Ballmer.

According to TMZ, doctors declared Donald Sterling "incompetent to have a voice in the sale" of the Clippers, leading the 80-year-old to be stripped of power. From TMZ:

We're told earlier this month Donald agreed to an examination by 2 prominent neurologists. He underwent extensive tests, including a CT and PET scan. We're told both doctors diagnosed Donald with Alzheimer's and concluded he may have had the disease for as long as 5 years. The doctors both concluded he did not have the ability to conduct the business of the team.

Donald Sterling's lawyer, Max Blecher, vehemently denied the reports of his client's poor mental state, telling Shelburne that Donald is "far from mentally incompetent."

Due to a clause in the Sterling family trust, Donald or Shelly can be removed from power if medical experts declared the mentally unfit. The doctors' diagnosis of Donald Sterling's Alzheimer's disease triggered the process.

McCANN: NBA's checklist before approving sale of Clippers

From ESPN.com's Shelburne:

Shelly Sterling announced on Friday that she has signed a “binding contract” to sell the Clippers to Ballmer for $2 billion. Any sale agreement, however, must be approved by the NBA’s Board of Governors by a three-quarters vote. The announcement of the sale agreement came just days before June 3, the date that the NBA’s Board of Governors was set to vote on ousting Donald Sterling from the league entirely. According to an official statement, the NBA is open to that possibility but will proceed with the vote as planned.

“Commissioner Silver has consistently said the preferred outcome to the Clippers proceeding would be a voluntary sale of the team," said NBA spokesman Mike Bass. "Shelly Sterling advised the NBA last night that an agreement had been reached with Steve Ballmer, and the NBA Advisory/Finance Committee met via conference call this morning to discuss these developments. We await the submission of necessary documentation from Mrs. Sterling. In the meantime, the June 3 special meeting of the NBA Board of Governors remains as scheduled.”

SI.com’s Michael McCann reported Thursday that the NBA could fast track the sale of the Clippers if it has a “favorable impression” about a prospective owner. Ballmer would seem to fit the criteria, having made a record offer and being previously vetted by the NBA in his attempt to buy the Kings.

Donald Sterling, 80, has owned the Clippers for 33 years, making him the NBA’s longest-tenured owner. But the NBA recently initiated a charge to terminate his ownership, outlining a list of actions that have have “damaged and continue to damage the NBA and its teams” while also listing off a series of negative impacts on the league. The NBA is taking issue with Sterling for the following reasons:

Disparaging African-Americans and minorities.

Directing a female acquaintance not to associate publicly with African-Americans or to bring African-Americans to Clippers games.

Criticizing African-Americans for not supporting their communities.

The first two items relate to comments made by Sterling to his girlfriend, V. Stiviano, in a private tape that was released by TMZ. The third item relates to comments made during an interview with CNN this month. The NBA is listing the following impacts of Sterling’s comments and behavior:

Significantly undermining the NBA’s efforts to promote diversity and inclusion.

Damaging the NBA’s relationship with its fans.

Harming NBA owners, players and Clippers team personnel.

Impairing the NBA’s relationship with marketing and merchandising partners, as well as with government and community leaders.

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