DALLAS — In a shocking turn of events one day before the season opener, Gersson Rosas turned in his resignation Tuesday as general manager of the Dallas Mavericks.A source said Rosas wanted more influence on the team and that he ultimately didn’t fit in with the direction owner Mark Cuban and president of basketball operations Donnie Nelson want to take the Mavs.“I think [Rosas] got the impression that he was going to have more power and more say-so, and I guess Cuban and Donnie wouldn’t budge on it,” the source said. “[Rosas] wasn’t at the office [Monday] and he wasn’t at the [tipoff] luncheon [Monday], so I thought that was interesting.”In a statement released by the Mavs, Rosas said: “I made the personal decision to resign as general manager of the Dallas Mavericks after determining that the position was not the best fit for me at this point in my career. The decision was made solely by me, as I firmly believe this change is in my best interest.” After Rosas was officially hired on Aug. 1, the Mavs said he would work under and report to Nelson, who had also served as the team’s general manager before Rosas was hired.But the source said the Mavs became worried how Rosas would fit into their structure if he wasn’t going to have a larger voice in player personnel and other basketball operation decisions.“I was disappointed when Gersson told me of his decision, but I understand and all of us wish him the best,” Cuban said in a statement released by the Mavericks.Cuban, Nelson, coach Rick Carlisle and his staff, players, other front office personnel and some season ticket holders attended Monday’s luncheon, but Rosas did not.Rosas, 35, was with the Mavs for only 90 days after he was hired from the Houston Rockets. The Mavs’ top brass boasted then how they were able to land one of the NBA’s rising young executives.But now, the parties have gone their separate ways just before the Mavericks open the season against the Atlanta Hawks.“Mark Cuban asked me to reconsider my decision, but graciously accepted my decision and we part as friends,” Rosas said. “I would like to thank Mark and the Dallas Mavericks for the opportunity.”Defense, rebounding keyThe Mavericks’ ability to rebound and play defense will go a long way toward their chances of securing a playoff spot.“Defense is going to be a huge factor for us; rebounding is going to be a huge factor for us,” Rick Carlisle said. “And we’ve got to do those two things well because that’s going to fuel how well we can play on offense.”The Mavs should get a defensive boost when center Brandan Wright (shoulder) and guard Devin Harris (toe) return. Both players, along with rookie point guard Shane Larkin, are out indefinitely. AAC will open earlyAmerican Airlines Center will open at 5:30 p.m. — 30 minutes early — for Wednesday’s opener. The doors are opening early because inclement weather is expected to hit the downtown Dallas area a little later.Hot dogs and sodas can be purchased for $1 each until 6:30 p.m.
Dwain Price, 817-390-7760 Twitter: @dwainprice