Kawhi Leonard describes his plan to return to the court this season while reiterating that he would like to finish his career as a Spur. (1:09)

SAN ANTONIO -- He slipped into the frame quietly. Attention was the last thing Kawhi Leonard wanted on this day, or really any day. But the San Antonio Spurs were taking their team picture and everyone in the organization needed to be there, in uniform and smiling, if only to prove they were indeed part of the team this year.

Leonard had been back in San Antonio for a few weeks by the morning of March 21. Several of his Spurs teammates had seen him working out in the team's facility. But picture day was the first time many had seen him in uniform since Jan. 13, the last of the nine games he played in this season.

"It was very brief," Spurs veteran guard Manu Ginobili said afterward. "But good to see him around."

The mystery surrounding Leonard and the right quadriceps injury that essentially cost him the entire season has fascinated and frustrated the entire league. Leonard has spoken publicly only a few times this season, and his statements did little to answer any of the larger questions his protracted absence raised.

On March 7, he said the injury and his current pain level were "hard to explain" but that "obviously I'm a competitor and if I could play, I would play." He didn't volunteer any of his feelings about the Spurs, or how they'd managed the situation. But when asked directly if he could see himself finishing his career with the Spurs, Leonard said, "Yeah, for sure."

play 1:09 Kawhi's plan to get back: 'Just play' Kawhi Leonard describes his plan to return to the court this season while reiterating that he would like to finish his career as a Spur.

Of course, Leonard has never said much, in general. If anything, his reticence became part of his brand and appeal. His game spoke for him. But without the ability to play much this season, the voices surrounding him became far more influential.

Spurs coach Gregg Popovich consistently affirmed his personal affection for Leonard but repeatedly expressed frustration about a rehabilitation process from an injury they never expected would take this long to heal. "You'll have to ask his group," Popovich consistently said when asked for updates, before reminding everyone that Spurs doctors had cleared him to play back in December.

Popovich presented San Antonio as a powerless, frustrated organization waiting for its franchise player and his camp to tell them what comes next. Leonard's group offered little explanation publicly or privately. And so it was left to Leonard to either rectify the situation or let it fester.

On the night of March 21, as Leonard walked through the corridors of the AT&T Center after the Spurs beat the Washington Wizards, ESPN asked him if the simplest explanation to this situation -- that he was hurt and genuinely didn't feel like he could play yet -- was actually the truest answer.

Leonard nodded, then said, "I mean, why else would I not be playing?"

"People are just looking for spin," Leonard continued. "I haven't been here long. I've been here six years. The Spurs have been here way longer than that. People are gonna go with that take first."

Finally, a small peek into the window of his thoughts. But before Leonard could expound on it, a Spurs communications staffer -- who ostensibly could not hear what Leonard was saying but saw he was talking to a reporter -- abruptly ended the conversation.

Leonard, who subsequently declined an interview request submitted through his agent and did not respond to a personal email, would not make another public appearance at a Spurs game after that night.

Over the past several months, ESPN has spoken to dozens of league sources, people close to Leonard and Spurs staffers. They describe a confounding situation, with mistakes made on both sides, and a looming showdown between one of the NBA's most prestigious franchises and one of the best players in the league who has never really flexed his muscles in this way, but just might have the power to alter the NBA landscape.

Kawhi Leonard's 2017-18 season was ruined by a quadriceps injury. Soobum Im/USA TODAY Sports

TO UNDERSTAND HOW the Spurs and Leonard got to this uncomfortable place, you must first understand the quadriceps injury that kept him out all season. And if you can do that, well, you might be way ahead of the specialists who have treated Leonard throughout this process. In conversations with multiple sources close to Leonard and the Spurs, there is some disagreement about the exact nature of the injury.

Leonard's camp believes his condition is the result of a series of contusions to the quadriceps that began with one very deep bruise in March 2016 that caused him to miss three games. Leonard was again listed with a "quad contusion" on the Feb. 6, 2017, injury report, when he was a late scratch before a game. But it wasn't until the end of last season when the severity of the injury became apparent.

According to multiple sources, Leonard's camp has come to believe the issue has more to do with an ossification, or hardening, in the area where the muscle has been repeatedly bruised, and then an atrophy, which in turn affected the tendons connecting the muscle to the knee.

The Spurs have always called the injury quadriceps tendinopathy, which is a disease of the tendon that has a degenerative effect on the muscle by keeping it in a constant state of exhaustion.

"Kawhi is the same person. The only thing that has changed about him is the people speaking for him now." A league source with knowledge of the situation

The treatment course for each diagnosis (a muscle issue vs. a tendon issue) is different, which has become another source of tension in the relationship.

Initially the Spurs' doctors were calling the shots, with Leonard following their protocols for most of last summer in his workouts in San Antonio with team staffers and San Diego with his longtime personal trainer. But things began to change in August as Leonard continued to experience discomfort, according to sources.

His agent, Mitch Frankel, and uncle, Dennis Robertson, began pressing the Spurs to consult outside opinions. Last fall, Dr. Keith Pyne, the managing partner of SportsLab NYC, which is affiliated with the Washington Nationals and New York Islanders, began consulting on the case.

Leonard briefly returned to the Spurs for nine games from mid-December through mid-January. The Spurs were conservative in their approach. He'd play one game, then sit out the next game regardless of how many days later it was scheduled. After scoring 19 points in 28 minutes in a win over Denver on Jan. 13, he complained of soreness in the area once again. He traveled with the team to Atlanta -- a game he was scheduled to sit out anyway -- and Brooklyn, but instead of playing against the Nets, Popovich announced at shootaround that Leonard was being shut down indefinitely.

"He didn't reinjure it or anything, but he was having pain, but not right after games, but maybe the next day at noon or that kind of thing and so the pain wasn't dissipating," Popovich said at the time. "It wasn't going in the right direction."

play 0:58 Popovich heartbroken by Kawhi news but looking ahead Gregg Popovich says it's horrible to be without Kawhi Leonard indefinitely but sheds some light on the situation by explaining how the team is preparing for the remainder of the season.

What Popovich did not say at the time, however, was that while Leonard was in New York, he saw Dr. Jonathan Glashow, an orthopedic surgeon and co-chair of Sports Medicine at New York City's Mount Sinai Medical Center who has professional affiliations with the New Jersey Devils and Philadelphia 76ers.

Frankel and Robertson arranged the consultation, according to multiple sources, and the Spurs were informed of the decision and the doctor's recommendations. From this point forward, Glashow and his team have guided the rehabilitation program, sources said. The Spurs have had staffers in New York to observe and assist in Leonard's work, which has primarily taken place at the NBA Players Association headquarters in midtown Manhattan.

The frustration on the Spurs' end stems from losing control of the medical care of their franchise player, and the way in which the entire process has been handled by Leonard's representation, according to multiple sources.

Said one Spurs staffer, "It's out of our hands."

Said another league source with direct knowledge of the situation, "Kawhi is the same person. The only thing that has changed about him is the people speaking for him now."

The frustration from Leonard's camp emanates from the resistance it felt it encountered from the Spurs over considering outside opinions, and the public questioning of the situation by Popovich, according to multiple sources.

Said one source close to Leonard, "The Spurs feel that they hire the best, that they do it better than anyone else. They deserve to have that reputation and that kind of ego. But they're just not very open-minded. They don't like others messing with their players."

Said another Leonard confidant, "They're alienating him. They're making him look bad. You have this seamless transition from the Duncan era to the new era, this homegrown superstar. Like, why would you alienate him?"

The confusion over the exact nature of the injury has only added to the frustration.

Spurs guard Tony Parker caused a stir when he said he had the same injury as Leonard, but "100 times worse" a few days after ESPN's Adrian Wojnarowski reported that Parker and Ginobili had confronted Leonard about his status during a tense team meeting on March 17. Several players, including Danny Green and Rudy Gay, later characterized the meeting as more of a discussion. However, Parker and Ginobili never addressed the tone or substance of the meeting, with Parker simply saying "that's family business."

Parker ruptured the tendon in his left quadriceps during the playoffs last year. Surgery was performed by the Spurs' team doctors and he returned to the court on Nov. 27.

"I don't think Kawhi and Tony Parker have the same injury," Frankel said. "That's clear, number one. I mean, that's crystal clear. Number two, I think the Spurs and Kawhi and Kawhi's doctors and everyone around Kawhi is just trying to get him healthy, jointly. It's not as simple as what's being written, so it's really just that he's gotta get his quad healthy. He's gotta get his tendon healthy, and that's the focus."

Spurs general manager R.C. Buford agrees.

"Our focus for all of our players is to provide them with the very best in player care for their entire career," Buford told ESPN early Tuesday morning. "Throughout this process with Kawhi, our goal has been to give him the best care and support available, no matter where that comes from."

Kawhi Leonard will likely either be rewarded with the largest contract in NBA history this summer or start next season's training camp in a different uniform. Soobum Im/USA TODAY Sports

IN 2014, LEONARD had a wrist injury that wasn't healing as anticipated, and his representatives, Frankel and Brian Elfus, asked for a second opinion. After mild resistance, the Spurs agreed and Leonard was seen by a specialist that his representatives were comfortable with. Leonard eventually returned to the Spurs after missing 15 games, and there were no issues afterward.

Spurs sources point to Elfus' departure in 2016 as a turning point in the relationship. He had maintained a strong relationship with the Spurs' front office and coaching staff and generally managed the relationship without incident. Frankel and Robertson were involved throughout Leonard's tenure in San Antonio as well, mostly during negotiations on the $90 million extension Leonard agreed to in 2015.

After Leonard and Elfus parted ways, Robertson and Frankel took over the day-to-day communication with the Spurs, and the relationship hasn't been nearly as healthy, according to Spurs sources. Elfus, who has since started his own sports management company, declined comment for this story.

Popovich's constant references to Leonard's "group" are a manifestation of the tension between the Spurs and Robertson and Frankel that has developed over the past year, according to Spurs sources.

"They're making him look bad. You have this seamless transition from the Duncan era to the new era, this homegrown superstar. Like, why would you alienate him?" A Leonard confidant

Multiple league sources also told ESPN that the Spurs have grown worried that Leonard's group has an ulterior motive to fray the relationship and get Leonard traded to a larger market such as Los Angeles (Leonard's hometown) or New York or Philadelphia (Robertson lives in New Jersey).

One source close to Buford said the longtime executive admitted to him that he's constantly losing sleep over how and why the relationship with Leonard has disintegrated.

For years, the Spurs saw him as the heir apparent to Duncan, both in his ability on the court and his low-maintenance personality off it.

"Kawhi just wants to get better and better and better," his mother, Kim Robertson, told ESPN after he was named Finals MVP in 2014. "He does not want to be a superstar. He does not want to be in the limelight. He just wants to be good at what he loves to do."

Those who talk regularly to Leonard still believe that's the case. Popovich stayed in close contact with Leonard, exchanging text messages throughout the season. So have teammates, including Danny Green and Dejounte Murray.

What the Spurs are trying to determine are the motives of the people speaking for him.

SO JUST WHO is Uncle Dennis, as he's known to folks in San Antonio? And what is his agenda for Leonard?

There are plenty of people willing to speak about Robertson and Frankel, but very few who will go on the record. Several current and former associates and colleagues describe Robertson as "difficult" and portray an ambitious family member trying to parlay his nephew's success into his own marketing company.

According to multiple agents at other firms who met with Robertson in the past few years, he was interested in starting a business similar to LeBron James' marketing company, LRMR, and enlisting their services because he was not a certified player agent. That didn't interest the agents who spoke to ESPN, because their firms had their own in-house marketing and business services.

"It was definitely the most unusual, toughest season by far since I've been here. I will keep it at that." Tony Parker

But even his detractors say Robertson has been devoted to Leonard since his father was shot and killed in 2008. And in turn, sources said Leonard seems devoted and loyal to Robertson.

"Kawhi really trusts him," one source close to Leonard said.

Robertson, Leonard's maternal uncle, disputes those negative characterizations. He points to his experience in banking (according to his LinkedIn profile, 22 years as a vice president of retail banking at Chase Bank and five years at Carver Federal Savings) and title as president of the Elite Athlete Division at his wife's company Protocol International, which offers business etiquette training and professional development, according to its website.

Robertson, who now sends all his emails from an address associated with Protocol, is pictured playing golf on one page of the company's website, which states:

"At Protocol International, our goal is to have fans cheering for you and impressed by your performance on and off the court. We teach universally accepted protocol and etiquette practices that allow athletes to consistently excel in various business and social engagements that include networking at combines, traveling with the team, dining with coaches and sponsors, as well as business meetings."

That type of brand development obviously hasn't translated with Leonard throughout this saga. Instead, Leonard's brand has taken a huge hit this season.

Leonard's sister, Miesha Slayton, often responds to the negative comments on Leonard's official Instagram fan page, which she manages. She wrote to one fan, who questioned why Leonard was in New York City instead of with the Spurs during the playoffs, "What makes you think he's not working to get back to his team? Make sure you speak Facts! Kawhi is still a Spur...."

On April 21 she posted the text, "Your negative comments will get you blocked. This page is for True Kawhi Leonard Fans!!"

In recent weeks National Basketball Players Association president Michele Roberts has offered advice and support to Robertson in managing the situation, according to multiple sources. But he has yet to formally ask Roberts to assist.

play 0:31 Popovich uncertain about Kawhi's return When asked about Kawhi Leonard returning to the Spurs, Gregg Popovich says you would have to ask Kawhi himself since he is rehabbing in New York.

FRANKEL HAS BEEN known primarily as a football agent over his three decades as the co-founder of Impact Sports. But within the past decade, the agency decided to expand to represent basketball players, and Leonard was seen as the centerpiece of the venture.

That expansion did not go as planned, however. According to records obtained by ESPN, six UCC liens have been filed against Frankel in Florida since 2011. Former Impact Sports employees contacted by ESPN attributed those financial troubles to Impact's venture into basketball. Records indicate Frankel borrowed money from companies such as Cobalt Sports Capital and JS Sports Funding.

Former NFL linebacker Andra Davis, who was with Impact Sports for his entire 10-year career, said he was asked whether he wanted to invest in the company's expansion into basketball. He chose to do that as a loan, not as an investment, because it was safer.

"I don't know [Kawhi]. I don't know whatever that situation or his injury and all that. But what I can say is the reason I feel good about doing the loan is because of Kawhi. Put it that way," Davis said. "I'm like, 'OK. You got Kawhi, one of the best players in the NBA, then I feel like they would've had a chance to get more top-notch guys.'"

Elfus' departure came around the same time several other football agents left the company. Ron Butler, Tony Fleming and Sean Kiernan all confirmed to ESPN that neither they nor their clients are associated with Impact Sports anymore. In fact, there doesn't appear to be an Impact Sports at all. The company website is under construction.

One of the investors in the agency, JS Sports Funding, seems to be controlling what remains of the company.

A Forbes article in February 2017 referred to Joseph Sutton as the senior managing partner of Impact Sports. He and his father, Jeff Sutton, the billionaire founder of the New York City-based Wharton Properties, invested $10 million in the agency, according to the Forbes article.

When contacted by ESPN, Joseph Sutton said Impact Sports is currently being "rebranded," but their initial vision for the agency to leverage their relationships in real estate to create new wealth for their clients has never changed.

"It's a very unique advantage that we have, those kinds of connections and access to capital and buildings and investments," Sutton said. "I'm gonna show [the client] how to preserve and sustain wealth, how to make passive income when [they're] on the court playing basketball."

They'd already done that with Leonard, Sutton said: He and Robertson make "seven figures" a year on a real estate investment Sutton presented them in Harlem. Property records obtained by ESPN show Robertson as a co-owner of several units in an apartment building on Madison Avenue in Harlem.

It's an intriguing business strategy in an industry that has turned volatile in recent years with agents increasingly offering to take less commission as a means to poach clients from one another, while several other high-profile agents have left the business altogether, while another, Andy Miller, under federal investigation in connection with the probe into college basketball.

The pitch clearly worked with Leonard. But without agents to run the day-to-day operations of the company, Impact Sports' two other NBA clients recently left the agency. Hawks forward Taurean Prince confirmed he is now with CAA. Nuggets guard Will Barton confirmed he is with Goodwin Sports Management.

Frankel admitted he is no longer with Impact even though he is Leonard's registered agent on file with the NBPA. Robertson confirmed he was a contractor for Impact Sports for several years before Frankel left the company. Now he says he has an arrangement with Frankel directly, where he's paid as a consultant.

If it seems hard to discern just who is speaking for Leonard, and what their individual agendas are, that's because it is. How much of that has contributed to the breakdown in the relationship between Leonard and the Spurs? That's what will determine how this story ends.

IT'S HARD TO appreciate just how embedded the Spurs are in the soul of San Antonio unless you visit and see the flags that stay up on front porches and in front windows on Houston Street all year long, like Christmas lights in July.

Drive by Albert Gonzales' mural of Tim Duncan, Tony Parker and Manu Ginobili at the corner of South St. Mary's Street and Pereida Streets and you'll see the work of a once-homeless artist who drew inspiration from his favorite team to get through that stage of his life and build his now-flourishing career.

Duncan is still wearing No. 21 in the mural. Parker still looks like the Frenchman who darted around defenders during the Spurs' championship runs. And Ginobili has hair.

Street art A post shared by Ramona Shelburne (@ramonashelburne) on Mar 23, 2018 at 11:42am PDT

Today the now-retired Duncan is wearing sweats whenever he drops by Spurs practices or games. Parker is coming off the bench, having ceded the starting job to youngster Dejounte Murray, and Ginobili is doing yoga in the locker room before games, trying to squeeze a few extra magic moments out of his 40-year-old body.

Leonard was supposed to be the bridge from the Duncan-Ginobili-Parker era. That's how the Spurs positioned and planned around him. Rather than rebuild and refresh the roster in the offseason, the Spurs assembled this season's team with the idea of maximizing his prime -- agreeing to new deals with LaMarcus Aldridge (32), Pau Gasol (36), Patty Mills (28) and Ginobili (40).

Popovich, 69, has contemplated retirement for the past few seasons, but said he'd stayed on because he kept promising players, including Aldridge and Leonard, that he'd be the coach if they signed with the Spurs. He has also signed on to coach Team USA in the 2020 Olympics.

Keeping Leonard never seemed to be an issue until this season. Yes, it was always going to be hard to convince ownership to agree to a $219 million contract, the supermax extension Leonard is eligible for this summer because he's been on an All-NBA team in two of the past three seasons. The Spurs are still a small-market team, and new Spurs chairman and controlling owner Julianna Hawn Holt filed for divorce from her former husband and the team's former controlling owner, Peter Holt, in February.

But if there was one player Popovich and Buford could go to ownership and tout as a beacon of stability and Spurs values who was worthy of such a financial investment, it was Leonard.

After the way this season has played out, however, it's hard to know what the future will bring for either side. Internally the Spurs are still optimistic Popovich can repair the relationship and find common ground with Leonard, as he did with Aldridge the previous summer.

The question then becomes whether the front office will go to ownership and seek approval for the five-year, $219 million extension, confident there won't be a reprisal of the tensions and frustrations that arose this year. And in turn, what Leonard's answer will be if such a contract is offered.

That is what's being discussed right now, and according to sources on both sides, there are no clear answers yet.

Kawhi Leonard's first season without Tim Duncan at his side resulted in MVP votes. Leonard's second season left his future in doubt. Ronald Martinez/Getty Images

DURING A STOP through Los Angeles at the beginning of April, a reporter asked Popovich which organizations he admired when he first started coaching.

"Utah Jazz," Popovich said. "I thought from top to bottom, it was a classy organization. You never heard anything out of there. Nothing negative. Kept their business to themselves, they worked hard. No showy stuff. They just did their work and they went home."

It was a revealing answer after a season like this one. All year Popovich had been out of his comfort zone, answering questions about Leonard and finding coded language to express his frustrations.

A few weeks earlier, before a loss to the Golden State Warriors, Popovich seemed downright wistful for the Duncan era.

"He was such a stalwart, such a foundation," Popovich said. "He exuded such a leadership in a quiet way that everybody just responded to his example. I think more than anything that's what was the basis for our long-term success."

Popovich used to say he'd retire at the same time Duncan did. That did not come to pass, so his challenge in the twilight of his career is to adapt the Spurs Way without him.

Like Duncan, Leonard seems wholly unconcerned with marketing and image. Yes, Jordan Brand did "The Claw" campaign for him. But Kawhi simply went along with the contractual obligations. Over the years, the only endorsement he seemed genuinely excited about was a deal with Wingstop, because he liked eating there.

Like Duncan, Leonard was always focused on basketball and left the business stuff to his representation.

ESPN reported in March that Leonard and his camp walked away from a four-year, $22 million extension of his current shoe contract with Nike's Jordan Brand. According to sources on both sides, talks abruptly broke down because Robertson did not feel the offer was worthy of the former Finals MVP.

The Spurs, of course, couldn't care less which shoe deal he signs or what kind of real estate investments he has made. They just want him to play basketball for them.

Does he still want that? And when he decides on an answer, who will speak for him?

Kawhi Leonard is one of three Spurs under head coach Gregg Popovich to win a Finals MVP award. Soobum Im-USA TODAY Sports

ALL OF THESE issues seemed small after Popovich's wife died on April 18, on the eve of Game 3 against the Warriors in the first round.

Her death was a gut check for the whole league, trivializing these playoffs and all the petty annoyances players and coaches lose sleep over. Who cares who starts at center? Or how many minutes Hassan Whiteside played? Or whether Leonard sat on the bench with his teammates during games, or trained in New York?

Erin Popovich had been ill for decades. Her respiratory condition kept her from traveling, and often, the climate in Maine, where they own a home, was easier on her system than San Antonio's.

While Popovich rarely spoke of her situation publicly, those close to him knew how much he carried with him every day. You could hear it in his speeches about leading a balanced life, in his values and the way he tried to create a family among the organization. Some of that was his military background. The team was his squadron to command. They were a band of brothers. But a lot of that was his deep love for Erin and the family they had together.

Popovich did not coach in the final three games of the playoffs this season. Those close to him say he's still processing everything.

Leonard had intended to leave New York, join the team and support Popovich if he coached one of the games after his wife's death, according to sources close to both men. When Popovich did not return, Leonard decided to stay and train. But the sentiment was an indication of the strength of their bond.

The situation with Leonard feels quite small in comparison to Popovich's grief. But eventually Popovich will need to decide whether he's up for trying to solve the situation with his star forward and whether he wants to make another go with him and the two keepers of the flame, Ginobili and Parker, assuming they return.

Parker had his head down as he left Oracle Arena following the Spurs' season-ending loss in Game 5. He is a free agent, but he would like to return for a few more years if the Spurs will have him back.

"It was definitely the most unusual, toughest season by far since I've been here," Parker said. "I will keep it at that."

Ginobili was in better spirits after the final game. All season, fans from his native Argentina made pilgrimages to watch him play. Tour companies organized group trips to San Antonio and several road cities, with the stands filled with raucous fans in blue and white, singing for their national hero.

For Ginobili, the decision on whether to keep playing is simple.

"It's just a matter of if I see myself as an ex-player or not," he said.

All year he's been fighting to sustain the Spurs' old magic. Because he loved it, and the way things were.

It's up to Leonard to decide whether he wants the same thing.

Adrian Wojnarowski contributed to this story.