(Photo by Noel Vasquez/Getty)

UPDATES: 5/31/14, 7:45 a.m. EDT. Donald Sterling has officially sued the NBA in federal court in Los Angeles. Click here for the 172-page complaint, courtesy of USA Today. The league has a formidable counter to Sterling’s suit in an indemnification agreement it has reached with the Sterling Family Trust, according to SI.com legal analyst Michael McCann. 6/5/14, 8:45 a.m. EDT. ESPN reports that Donald Sterling has officially dropped his suit against the NBA and will accept the sale of the team to Steven Ballmer. 6/10/14, 10:00 a.m. EDT. Not so fast. Sterling’s suit against the NBA is reportedly back on after he withdrew his support of a Clippers sale to Ballmer.

Covington & Burling, Greenberg Glusker Fields Claman & Machtinger, Kirkland & Ellis and Proskauer Rose are advising on what is shaping up as the most lucrative sale of a professional sports team in U.S. history as former Microsoft CEO Steve Ballmer has agreed to pay $2 billion to acquire the National Basketball League’s Los Angeles Clippers.

Shelly Sterling, the wife of disgraced Clippers owner Donald Sterling, confirmed Friday that she has reached a “binding contract” to sell the team to Ballmer, who relied on a team of Covington lawyers to beat out a crowded field of bidders. The NBA has said it will approve the deal, although it still must be finalized by the league’s owners.

With the purchase price applying solely to the Clippers—neither the team’s practice facility nor the 19,000-seat Staples Center that serves as its home court are included in the deal—the pure franchise value of the transaction tops the $2.15 billion that Major League Baseball’s Los Angeles Dodgers sold for in 2012. (That deal, which as previously reported by The Am Law Daily yielded small roles for for Covington and Proskauer, included $412 million in debt and a $150 million parking lot joint venture involving the new owners.)

The Clippers sale comes a little more than a month after tape recordings that captured Donald Sterling making racist comments to an aggrieved mistress became public. The ensuing controversy prompted the NBA to hire Wachtell, Lipton, Rosen & Katz to investigate the circumstances surrounding Sterling’s comments. As a result of that inquiry, the league banned the Beverly Hills lawyer for life and fined him $2.5 million. Earlier this month, the NBA hired former Patterson Belknap Webb & Tyler managing partner Richard Parsons to serve as the team’s interim CEO.

“It’s been an unbelievable four weeks,” says Pierce O’Donnell, a former Kaye Scholer partner and longtime Los Angeles trial lawyer who joined Greenberg Glusker in March. The firm, a highly regarded local boutique, had done previous work for Shelly Sterling through name partner and prominent entertainment litigator Bertram Fields and private client practice chair Laura Zwicker.

O’Donnell worked with Bob Baradaran, a real estate transactional partner elected to serve as Greenberg Glusker’s managing partner earlier this year, to lead a cross-practice Greenberg Glusker team advising Shelly Sterling as she assessed a bevy of bidders—a high-profile group that encompassed Oprah Winfrey, David Geffen and Magic Johnson—angling to buy the Clippers.

“For the bankers, the buyer, the seller and the legal teams, I don’t think anyone has ever seen anything like this,” says Baradaran, referring to the circus-like atmosphere that has swirled around the sale process. “It’s definitely the most interesting deal I’ve ever done.”

Baradaran, who has advised MLB’s Oakland Athletics and Major League Soccer’s San Jose Earthquakes on their efforts to build new stadiums, and Greenberg Glusker face an uncertain timeline for completing the sale of the Clippers to Ballmer.

O’Donnell says the firm wants to close the transaction “as soon as possible,” and is hoping that the NBA’s board of governors approves Ballmer as a franchise owner by mid-July. “I don’t expect [Ballmer] to have any problems being approved,” O’Donnell adds.

Whether Shelly Sterling can actually sell the team without the her estranged husband’s consent is an open question. The couple are separated but not divorced—a legal wrinkle that may affect future litigation involving the fate of the team and the NBA’s effort to force a sale to a new owner of which it approves.

Shelly and Donald Sterling have made conflicting statements about their intentions regarding a sale. Their diverging interests reportedly hastened Manatt, Phelps & Phillips’ decision to withdraw as the family’s counsel in mid-May. The firm has traditionally handled Clippers-related work for the Sterlings through Robert Platt, a Los Angeles-based Manatt litigation partner who has served as general counsel for the team.

Though Platt did not immediately respond to a request for comment, Greenberg Glusker’s Baradaran says Manatt did not play an advisory role in connection with the proposed sale to Ballmer.

Meanwhile, new questions arose Friday about what authority Donald Sterling—who reportedly approached high-powered firms such as Quinn Emanuel Urquhart & Sullivan and Glaser Weil Fink Howard Avchen & Shapiro about launching a massive antitrust case against the league to block a forced sale of the team—has to stand in the way of a deal.

USA Today and ESPN both reported that after undergoing neurological testing this month, Donald Sterling had been declared mentally unfit to handle matters for the Sterling Family Trust, which owns and operates the Clippers. (While Sterling was known to be undergoing treatment for prostate cancer, reports emerged Friday afternoon that he is also suffering from symptoms of Alzheimer’s disease.)

If Donald Sterling’s authority over the trust has been rescinded, Shelly Sterling would be sole trustee empowered to negotiated with potential bidders, including Ballmer. Asked about the mental state of his client’s estranged husband, Greenberg Glusker’s O’Donnell’s offered a terse response.

“Donald Sterling was removed as cotrustee on Thursday, and that’s all I’m going to say about that,” says O’Donnell, who at one point in the interview jokingly referred to himself as a “big-mouthed Irishman.”

O’Donnell was less reticent about discussing Maxwell Blecher, a noted antitrust lawyer and name partner at Los Angeles-based Blecher Collins Pepperman & Joye whom Donald Sterling retained for a possible court battle with the NBA. “I’ve known Max for years, and he’s a great lawyer,” O’Donnell says. “I just don’t agree with him on the law here.”

Blecher, who earlier in the week declared that his client would fight the NBA’s plan to force a sale of the Clippers “to the bloody end,” did not respond to a request for comment Friday about the team’s proposed sale to Ballmer. Blecher, who helped Sterling move the Clippers from San Diego to Los Angeles back in 1984, did tell ESPN via email that reports of his client’s mental incapacity were “grossly exaggerated.”

NBC News then first reported late Friday night that Blecher is preparing to file a $1 billion suit against the NBA over its decision to force a sale of the team. At the time this story was slated for publication, it appeared that the suit did not touch on the pending sale of the team to Ballmer, although another action could be imminent.

Another attorney representing Donald Sterling, Babak “Bobby” Samini of Costa Mesa, Calif.-based Samini Scheinberg, declined via email to comment about the proposed sale to Ballmer. Douglas Walton, a key Sterling lieutenant, in-house lawyer for his real estate company and board member for Sterling’s nonprofit foundation, also did not respond to a request for comment on the matter.

Kirkland & Ellis corporate partners David Fox, Rick Madden and Andrew Herman are serving as counsel to Bank of America/Merrill Lynch in its role as financial adviser to the Sterling Family Trust on its deal with Ballmer. Bianca Levin-Soler, a Kirkland associate, is also working on the transaction. (Kirkland advised on the $550 million sale of the Washington Wizards in 2010.)

As for Ballmer, the former Microsoft executive turned to Covington for counsel last year on his ill-fated effort to acquire the NBA’s Sacramento Kings and move them to Seattle, according to our previous reports. The league eventually approved the $534 million sale of the team to software entrepreneur Vivek Ranadive, who kept the franchise in California’s capital.

The Covington team advising Ballmer this time around is led by corporate partners Douglas Gibson and Peter Zern—two veteran sports dealmakers—M&A special counsel Scott Roades, tax partner Robert Heller and special counsel Jeffrey White, employee benefits partner Michael Francese, litigation partner Benjamin Block, environmental practice cochair and special counsel E. Donald Elliott and trusts and estates senior counsel Doris Blazek-White.

Covington has close ties to the NBA. The league’s general counsel, Richard Buchanan, once worked at the firm. In addition to counseling Ballmer on his Kings bid, Covington also advised on the $450 million sale of the Golden State Warriors in 2010.

The NBA itself is being advised by longtime outside counsel Proskauer Rose in connection with the Clippers ownership drama. Joseph Leccese—who was elected as the firm’s youngest-ever chairman in 2010 and who serves as cohead of its powerful sports law group—is leading a team working on the matter. The other Proskauer attorneys include corporate partners Wayne Katz and Jon Oram, tax partners Mitchell Gaswirth and Amanda Nussbaum, litigation partner Michael Firestein and associates Amy Dunphy, Susan Gutierrez, Zachary Kleiman, Jason Krochak, David Mordkoff and Frank Saviano.

The Am Law Daily reported in April on Proskauer’s role advising the NBA on the $550 million sale of the Milwaukee Bucks to two hedge fund billionaires—a whopping sum for a franchise that finished the season with the league’s worst record. Like many other pro sports leagues, the NBA has seen the value of its franchises soar as advertisers invest in live sports programming. The Deal reported in May that the owners of the NBA’s Minnesota Timberwolves are considering their strategic options.

Of course, some observers believe the Clippers’ purchase price is too much and that the $2 billion price tag is unlikely to be fetched by other franchises in different situations.

“Ballmer’s offer is a staggering price, but may be an outlier, and not necessarily a benchmark against which other team sales in this or other leagues should be measured,” said a statement by DLA Piper corporate partner Charles Baker in New York, who has represented buyers and sellers of teams in all of North America’s major pro sports leagues and has no role in the Clippers matter. “The speed of this transaction is heightened by the publicity of a [Los Angeles-based] trophy asset and the additional drama of rescuing the team from a controversial owner.”

NBA commissioner Adam Silver, who took over the league’s top leadership role earlier this year from former Proskauer partner David Stern, has won accolades for his handling of the Sterling crisis.

Silver’s ascent from Cravath, Swaine & Moore associate to NBA executive was recently profiled in a Sports Illustrated cover story. In the piece, Silver discusses his relationship with his father, Edward Silver, a legendary New York labor and employment lawyer and former Proskauer chairman.