The swingman was fined $25,000 for "public statements detrimental to the NBA," the league announced on Tuesday. On Aug. 28, Jackson said that he would like to be traded to Cleveland, New York or one of the Texas teams.
Warriors coach Don Nelson said on Monday that Jackson is still his captain.
"I've talked to him," Nelson said. "I don't anticipate any problems."
Less than a year ago, Jackson signed a three-year extension worth $28 million.
But the league said in its statement: "Players are not permitted to make trade requests publicly" and cited the case of Ron Artest who was fined in the 2005-06 season for requesting a trade from the Pacers through the media.
Technically, Jackson can appeal the $25,000 fine. But under a change made to the collective bargaining agreement in 2005, Stern himself is the only court of appeal for instances in which he fines a player $50,000 or less or issues a suspension of 12 games or less for off-court behavior that forces him to "preserve the integrity of, or maintain public confidence in, the game of basketball." Only penalties that exceed those thresholds can be appealed through a grievance arbitrator.
Jackson averaged a team-high 20.7 points per game, to go with 6.5 assists and 5.1 rebounds per contest.
Information from ESPN.com's Chris Sheridan contributed to this report.