The NBA said the Rockets don't have the league-required eight available players to move forward with the game. According to the league, three Rockets players returned tests that were either positive or inconclusive for the coronavirus.
In addition, four other Rockets players are in quarantine under the league's contact tracing protocols, and Chris Clemons was unavailable due to an Achilles injury.
The league also said Rockets superstar James Harden was unavailable "due to a violation of the Health and Safety Protocols" after the NBA reviewed video of Harden partying without a mask.
The video of Harden partying, which was published by Black Sports Online and has been circulating on social media, is reportedly from a Houston club's Christmas party held this week. The NBA's COVID-19 protocols forbid players and coaches from going to bars, lounges, clubs or social gatherings of more than 15 people.
On Wednesday, Harden issued a statement on Instagram saying "everyday it's something different" and the event wasn't at a strip club.
"One thing after another. I went to show love to my homegirl at her event [not a strip club] because she is becoming a boss and putting her people in position of success and now it's a problem," Harden wrote. "Everyday it's something different. No matter how many times people try to drag my name under you can't. The real always end on top."
The NBA made the announcements at about 5:30 p.m. EST, with tipoff scheduled for 8 p.m. in Houston.
The Thunder will now return to Oklahoma City on Wednesday night before traveling to Charlotte on Friday for their new season opener against the Hornets on Saturday.
The league didn't provide a timetable for when the Rockets can return to competition. Houston is scheduled to play at the Portland Trail Blazers on Saturday night.