Mavs owner Patrick Dumont has admitted his management's mistake in trading Luka Doncic away last season. In an attempt to fix the damage done to the team's championship hopes, Dumont and the Mavs fired general manager Nico Harrison on Tuesday.NBA insider Shams Charania tweeted that Dumont addressed trading Doncic as a mistake."The Mavericks are firing Harrison nine months after the jarring and stunning Luka Doncic trade- a move for which Dumont took accountability and accepted as a mistake in a court-side interaction with a fan on Monday night," Charania wrote.Luka Doncic's move to LA from Dallas was arguably the biggest trade made in the league in the last two decades and one of the biggest trades in history. The Mavs received a 2029 draft pick, Max Christie and 10-time All-Star Anthony Davis in return for Doncic.So far, the Lakers have been the only ones benefiting from the deal. Doncic underwent a physical transformation during the offseason. He shed significant weight and became more athletic on the court.Doncic has been tearing the league apart as a result of his offseason work. He is averaging 37.1 points, 9.4 rebounds and 9.1 assists per game on 49.1% shooting. He is on track for a possible MVP season, while the Mavs have become one of the league's worst teams.Anthony Davis is frequently in and out of games due to injuries, playing just 14 games since the trade, while his team holds the 13th place in the Western Conference with a 3-8 record.Mavs promote executives as interim leaders for basketball operationsSoon after delivering the news on Nico Harrison's firing, Shams Charania revealed the people selected to take his place. The Mavs have promoted Michael Finley and Matt Riccardi to lead the basketball operations in the meantime."The Mavericks and Patrick Dumont have 10:30 am central time meetings to appoint executives Michael Finley and Matt Riccardi to lead basketball operations in interim, sources tell me and Tim MacMahon," Charania wrote.Shams Charania @ShamsCharaniaLINKThe Mavericks and Patrick Dumont have 10:30 am central time meetings to appoint executives Michael Finley and Matt Riccardi to lead basketball operations in interim, sources tell me and Tim MacMahon.Finley is a former Mavericks player who serves as the vice president of player personnel in Dallas. Matt Riccardi served as an assistant manager of the franchise under Harrison.