Had it happened six months ago, Monday would have been a red-letter day for Kawhi Leonard and the Spurs.

On the third-year anniversary of the last contract he signed, Leonard officially became eligible for the most lucrative deal in basketball.

Known formally in Collective Bargaining Agreement legal-ese as the “Designated Player Exception” — but virtually everywhere else more colloquially as the “supermax” extension — the new contract Leonard could now earn from the Spurs is worth $221 million over five years.

Leonard qualified for it by being named to the All-NBA team in two of the previous three seasons.

It would be the largest contract handed out in Spurs history.

And had this date come in, say, February — before the words “disgruntled All-Star forward” became applied as a permanent prefix to Leonard’s name — Spurs general manager R.C. Buford and coach/president Gregg Popovich would have gladly accepted his autograph on such a contract, locked up one of the NBA’s most dynamic two-way players for the remainder of his prime and set their sights on taking down Golden State in the Western Conference.

None of that happened Monday.

Instead, the standoff between the Spurs and their franchise player continued unabated, as it has for the duration of this summer of South Texas’ discontent.

Leonard, through his representatives, has expressed his desire to be traded away from San Antonio. He has made no indication of backing away from that request.

The Spurs, meanwhile, appear hesitant to empty the vault for a player who played in only nine games last season while rehabbing a perplexing quadriceps injury under the care of outside medical staff and under the figurative cloak of darkness in New York.

The discord came to a head in March, when Leonard seemed on pace to join the Spurs for their playoff push but instead kept having his return date postponed by his medical team.

After a March 17 victory over Minnesota, Spurs players — led by veteran point guard Tony Parker — held a team meeting with Leonard present, asking the two-time All-Star to clarify his status going forward.

Leonard was not happy with what he viewed as an ambush, sources said, and soon returned to New York to continue rehab. In mid-June, Leonard’s representatives began publicly seeking a trade.

The Spurs fielded offers for Leonard before, during and immediately after the June 21 draft. They listened to more pitches at the dawn of NBA free agency earlier this month.

So far, they have yet to find a deal to their liking that both A) Helps rebuild the roster in the aftermath of Leonard’s hypothetical departure and B) Keeps them playoff-competitive in the near term.

With Leonard and his camp evidently intractable in their desire to relocate, the Spurs will continue hearing offers with the hope of either finding a landing spot for their 27-year-old star player before the opening of training camp in September, or at least smoothing things over with him.

It is in the latter of these two endeavors that $221 million would seem to help.

By league rule the Spurs are the only team that can offer Leonard supermax money. If he is traded, Leonard forfeits his claim to it.

If Leonard is dealt, the most he could make via an extension with his new team is $108 million over four years. If Leonard is dealt but opts to become a free agent next summer, the most he could earn would be $190 million over five years.

In the near-term, Leonard is leaving a veritable Fort Knox on the table by pushing for a trade.

Leonard’s team of advisers — including his agent, Mitch Frankel, and his uncle and business manager, Dennis Robertson — reportedly believes the league’s most low-key superstar can over time make up the financial difference in endorsement money and a new shoe deal if he moves to a higher-profile market.

There is growing suspicion among a collection of NBA agents — a naturally suspicious group — that Robertson is aiming to build his own marketing company with his nephew as its signature client, and would like to position Leonard in a glamour market to do so.

Multiple agents say Robertson — a former banking executive — has approached other players about wanting to be their manager.

At the same time, Leonard is peripherally involved in a lawsuit between his former agent, Brian Elfus, and Elfus’ former agency, Impact Sports Basketball LLC.

In the suit, filed last month in Florida, Elfus accuses the agency of failing to pay him commissions owed from the $94.3 million deal negotiated with the Spurs on Leonard’s behalf in July 2015.

Elfus has not represented Leonard since 2016. He is seeking $5 million in damages from Impact.

The suit also alleges Leonard’s uncle, Dennis Robertson and mother, Kim Robertson, have been on the Impact payroll for the past five years.

None of this came close to untangled Monday, when Leonard became eligible for a payday it now appears he will never see and doesn’t seem to want.

In a turn of events that would have seemed shocking even six months ago, Leonard’s once-anticipated supermax day transformed into something else entirely.

Just another meaningless Monday.

Jeff McDonald is a San Antonio Express-News staff writer. Read more of his stories here. | Jmcdonald@express-news.net | Twitter: @JMcDonald_SAEN