Gersson Rosas resigned as general manager of the Dallas Mavericks on Tuesday, just three months into his new job.

Rosas was hired Aug. 1 to fill a position that had been vacant since former coach and GM Don Nelson left the franchise eight years ago. Most of those duties fell to Nelson’s son, Donnie, the president of basketball operations.

Dallas owner Mark Cuban asked the younger Nelson to find an addition for the front office with stronger organizational skills, and Nelson came back with Rosas, who had been an assistant to general manager Daryl Morey in Houston.

The 35-year-old Rosas, who reported to Nelson, said in a statement issued by the team that the job “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,” Rosas said. “Mark Cuban asked me to reconsider my decision, but graciously accepted my decision and we part as friends.”

Rosas, a native of Colombia, spent nine years with the Rockets, rising from an intern to vice president of basketball operations. Rosas also spent time as general manager of the Rockets’ developmental team.

LeBron, Samsung team up again

LeBron James and Samsung are partners on a new ad campaign as part of James receiving his second NBA championship ring.

The company is showing off a variety of uses of its latest devices — Galaxy Note 3, Galaxy Gear and Galaxy Note 10.1.

A two-minute ad, titled Always On, puts a spotlight on the life of James as he interacts with family, friends and teammates using the latest technology from Samsung throughout his day, personally and professionally. The ad was scheduled to run for the first time Tuesday night on TNT after James and his Miami Heat teammates received their rings.

In the fall of 2012, Samsung partnered with LeBron to celebrate his first NBA championship. After the ring ceremony on TNT, the 90-second Galaxy Note II commercial aired.

Jazz exercise options on players

The Utah Jazz have exercised their fourth-year contract options on guard Alec Burks and center Enes Kanter.

The team announced the move on Tuesday, a day before they tip off the season against Oklahoma City. The options for Burks and Kanter are both through the 2014-15 season.

A former standout at the University of Colorado, Burks was the 12th overall pick by Utah in 2011. The 22-year-old averaged seven points and 2.3 rebounds a game last season.

Kanter was the No. 3 pick in 2011. The 21-year-old big man averaged 7.2 points and 4.3 rebounds in 2012-13.

Warriors’ Barnes out two games

Harrison Barnes will miss at least the first two games of the regular season for the Golden State Warriors with a left foot injury.

Warriors coach Mark Jackson told reporters following Tuesday’s practice that shooting guard Klay Thompson will start in the season opener against the Los Angeles Lakers tonight. Jackson also said that Thompson already had earned the nod.

Pistons owner donates to school

Detroit Pistons owner Tom Gores is donating $250,000 to support the Jalen Rose Leadership Academy.

The funding announced Tuesday from Tom and Holly Gores aims to boost the growth and development of the public charter high school in Detroit. The money is expected to be used for infrastructure improvements, personnel recruitment and retention, and other needs.

The school was founded by former NBA player Jalen Rose. After playing at the University of Michigan as part of the Fab Five, Rose played for six teams during a 13-year NBA career, including six years with the Indiana Pacers.