Trail Blazers All-Star forward LaMarcus Aldridge sprained his left ankle early in Portland's loss to the Washington Wizards on Tuesday night.
Aldridge let out a yell and fell to the floor after landing on Trevor Booker's foot less than two minutes into the first quarter.
The Blazers said X-rays on the ankle were negative, but he did not return and will not travel with the team to Golden State on Wednesday.
"I'm going to get back as soon as I can!" Aldridge wrote on his Twitter account after the game.
The crowd in the Rose Garden was silent while Aldridge was lying on the floor, but let out an audible groan as the replay was shown. After a couple minutes, Aldridge was helped off the floor by teammates and athletic trainer Jay Jensen.
Blazers owner Paul Allen looked in on Aldridge while he was getting treatment, according to Blazers' broadcasting.
Without Aldridge, the Blazers struggled, falling 124-109 to the Wizards.
"I think when he went down the life went out of us," center Marcus Camby said. "It's sad but true."
Aldridge was averaging 23.3 points and 8.6 rebounds going into the game. He has reached double figures in points in all of Portland's games this season.
Aldridge was chosen to his first All-Star game on Feb. 9, becoming the 15th Trail Blazer to earn the honor. He has also been selected as one of 20 finalists for a spot on the U.S. Olympic men's basketball team for the London Olympics.