Longtime Dallas Mavericks president of basketball operations Donnie Nelson is out after 24 seasons with the franchise, the team announced Wednesday.

Nelson's departure comes after internal friction due to the increasing decision-making influence of Mavericks director of quantitative research and development Haralabos Voulgaris, sources told ESPN.

Voulgaris, a former professional gambler hired by the Mavs in 2018, has reported directly to owner Mark Cuban and communicated directly with coach Rick Carlisle despite Nelson's objections, sources said.

The decision for Nelson to leave the franchise was made Sunday, sources said.

Nelson worked for the Mavericks for 24 seasons, serving as an assistant general manager and assistant coach before being promoted to president of basketball operations. He remained Cuban's top basketball executive for years after the acrimonious departure of his father, Don, the Mavs' head coach and general manager from 1997 to 2005.

"I just want to thank Donnie for his 24 years of service to this organization," Cuban said in a statement. "Donnie has been instrumental to our success and helped bring a championship to Dallas. His hard work, creativity and vision made him a pioneer. Donnie will always be a part of the Mavs family and I wish him all the best."

Donnie Nelson has been widely credited for scouting and pushing for the two biggest acquisitions in Mavericks' history: the draft-day trades for Dirk Nowitkzi and Luka Doncic 20 years apart.