Nico Harrison is out as general manager of the Dallas Mavericks, the team announced Thursday, ending a three-year tenure that delivered two NBA Finals appearances and reshaped the franchise around Luka Dončić. No reason was given. His departure removes the executive who executed the Kyrie Irving trade, hired Jason Kidd, and convinced Klay Thompson to leave Golden State for Dallas last summer.

Harrison joined Dallas in June 2021 from Nike, where he ran North America basketball for 19 years and maintained direct relationships with nearly every All-Star in the league. Owner Mark Cuban hired him without traditional front-office experience, betting that Harrison's player relationships would unlock deals other GMs couldn't. The bet paid. Harrison traded Kristaps Porziņģis to Washington in February 2022, clearing $31 million in salary flexibility. Eleven months later, he sent five players and draft capital to Brooklyn for Irving, a move that cost Dallas Jalen Brunson in free agency but gave Dončić the co-star Cuban had promised. Dallas reached the Western Conference Finals in 2024, then the Finals in 2025, losing both times but establishing a three-year championship window.

The timing matters. Dallas is $8 million over the luxury tax and faces a $180 million payroll next season if the roster stays intact. Thompson is on a three-year, $50 million deal. Dončić signed a five-year, $215 million supermax extension in 2021. Irving's contract runs through 2027 at $37 million annually. Harrison's successor inherits a capped-out contender with no draft picks until 2027 and limited trade assets beyond Dereck Lively II, who Dallas will not move. The new GM's first decision will be whether to extend Kidd, whose contract expires after next season, and whether to retain assistant coach Sean Sweeney, whom five teams have already contacted about head-coaching vacancies.

Harrison's departure also removes the Mavericks' strongest Nike connection at a moment when the franchise is renegotiating its arena naming rights. American Airlines' deal expires in 2031, but Cuban—who sold his majority stake to Miriam Adelson's family in December 2023 for $3.5 billion—had been exploring early renewals to lock in higher rates before the Las Vegas expansion team enters the market in 2027. Harrison had been involved in those conversations, using his Nike relationships to model what a potential sneaker-branded arena might command. That path now requires a different interlocutor.

The Mavericks are interviewing candidates. Expect Dennis Lindsey, the former Utah Jazz GM who now consults for multiple franchises, to receive a call. Michael Finley, Dallas's vice president of basketball operations and a former Mavericks player, becomes the internal favorite by default. Toronto assistant GM Jeff Weltman, who left Orlando last year, is another name circulating in agent circles. Whoever takes the job will inherit a Finals-caliber roster with no financial flexibility and a two-year window before Dončić turns 28 and extension talks begin again.

The Mavericks open training camp in 147 days. The new GM will be in place by late May, which gives roughly 90 days to evaluate the coaching staff, finalize summer league rosters, and decide whether Dallas's $4.2 million taxpayer mid-level exception goes to a backup center or a wing defender. Harrison built a contender in three years. His successor's job is simpler and harder: keep it together long enough to win.