Don Nelson. Image via: Sam Forencich/ NBAE via Getty ImagesDon Nelson, the second-winningest coach in NBA history, died Sunday at age 86, his family announced. Luka Doncic learned of the news while speaking to reporters and immediately offered condolences to the family of the Hall of Fame coach who once wore Doncic's sneakers in protest of his trade out of Dallas.The tribute carried extra weight given Doncic's ties to the Nelson family. He recently partnered with Nelson's son, longtime Mavericks executive Donnie Nelson, to buy Italian club Vanoli Cremona. A cause of death has not been disclosed.Luka Doncic sends heartwarming tribute to Don NelsonDoncic's connection to Nelson went beyond typical player-to-legend admiration. Nelson became one of Doncic's most vocal defenders after Dallas stunned the league by trading him to the Los Angeles Lakers in 2025. During the 2025 NBA Finals, Nelson accepted the Chuck Daly Lifetime Achievement Award while wearing Doncic's signature shoes, calling the trade a "tremendous mistake."Doncic reflected on that support in his own tribute. It’s a sad day for basketball with the passing of Don Nelson. “I have so much respect for him and everything he did for the game, especially the way he believed in international players. I’m grateful for the time I spent with him,” he said, adding that he was grateful for the time they spent together and had deep respect for how Nelson championed international players. “Thinking of the entire Nelson family today. I loved getting to know you, Coach.”The Mavericks organization echoed that sentiment. Governor Patrick Dumont said Nelson brought "a winning culture to Dallas" that still shapes the franchise today. NBA commissioner Adam Silver credited Nelson with revolutionizing the sport, noting his "fearlessness, ingenuity and deep conviction" across nearly five decades in the league.Dirk Nowitzki, who Nelson coached during his rise to superstardom in Dallas, delivered one of the day's most personal tributes. "You didn't just draft me. You believed in me," Nowitzki wrote, crediting Nelson with giving him the freedom to develop into a Hall of Famer.Nelson's bond with the Doncic era traces back further than his coaching tenure. Donnie Nelson helped engineer the 2018 draft-night trade that sent Trae Young and a future first-round pick to Atlanta for the rights to Doncic, a move that reshaped the Mavericks for a decade.Stephen Curry remembers Don NelsonGolden State's ties to Nelson run just as deep. He coached the Warriors across two stints, including the "We Believe" run in 2007 that produced the biggest upset in NBA playoff history when the eighth-seeded Warriors knocked off Doncic's old team, the 67-win Mavericks.Stephen Curry, who Golden State drafted in 2009 during Nelson's second stint as coach, credited Nelson directly for his opportunity. "He had an immeasurable impact on the sport," Curry said, recalling that Nelson challenged him from his first day despite a reputation for being skeptical of rookies.Warriors coach Steve Kerr, who also played briefly under Nelson, praised his lasting influence on the modern game. "So much of what is now commonplace in the modern NBA can be traced back to the way Nellie approached the game," Kerr said.The Warriors organization released its own statement calling Nelson "an iconic figure in Warriors history" whose innovative approach shaped both the Run TMC era and the 2007 upset squad. The team pointed to his 1,335 career wins and his role in popularizing small-ball lineups that influence today's league.Is Don Nelson's cause of death revealed?Nelson's family has not disclosed a cause of death. He is survived by his wife, Joy, and his family, including Donnie Nelson.Nelson's coaching résumé remains one of the most decorated in league history. He won three Coach of the Year awards, seven consecutive division titles with Milwaukee from 1980-86, and built the Warriors and Mavericks into playoff contenders during his respective tenures. His No. 2 ranking on the all-time wins list sits behind only Gregg Popovich.DetailInfoNameDon NelsonAge at death86DiedSundayCause of deathNot disclosedRegular-season coaching wins1,335 (2nd all-time)Teams coachedMilwaukee Bucks, Golden State Warriors, Dallas Mavericks, New York KnicksMavericks tenure1997-2005Hall of Fame induction2012NBA Coach of the Year awards3Championships won (as player, Boston Celtics)5For now, the tributes from Doncic and Curry stand as the clearest sign of how far Nelson's influence reached, from the players he drafted to the ones he simply refused to give up on decades later.