China has wiped the Celtics from its TV service without explanation following a damning tweet from Boston player Enes Kanter.
Kanter on Thursday slammed Chinese President Xi Jinping as a "brutal dictator" and declared that "Tibet belongs to the Tibetan people", risking reigniting tensions between Beijing and the NBA.
The league and China have previously traded words in public after one team official spoke out in support of Hong Kong democratic protesters last year.
It resulted in one team being banned from being broadcast in China.
It's now happening for a second time with the Celtics disappearing from the live stream roster published by NBA broadcaster Tencent.
China's response has been swift.
Coverage of the games had been downgraded to text and photo only, a status currently applied to the Philadelphia 76ers, where Morey is now president.
A handful of confused fans asked on Tencent's website and Weibo social media page why the streams were pulled.
When asked about Kanter's comments, the Chinese foreign ministry spokesman said: "His ridiculous allegation is not even worth refuting." "We welcome all friends from all countries to visit Tibet without prejudice and with an objective stance," Wang Wenbin said during a regular press conference.
It underscores the uneasy relationship between the NBA and China, where the league remains wildly popular.
In 2019, Chinese state broadcasters dropped the NBA after Daryl Morey, then general manager of the Houston Rockets, tweeted a message of support for pro-democracy protesters in Hong Kong.
The fallout from that crisis continues, with Tencent no longer streaming games involving the Philadelphia 76ers, where Morey is now the president of basketball operations. Tencent had previously banned the Rockets before Morey moved from Houston to Philadelphia.
Kanter has previously spoken out to voice support for human rights causes and his messages on social media this week attacked China over what he claims are human rights violations in Tibet.
Tibet has alternated over the centuries between independence and control by China, which claims it "peacefully liberated" the region in 1951 and brought infrastructure and education to the previously underdeveloped region.
But human rights campaigners and exiles have accused China of religious repression, torture, forced sterilisation and cultural erosion through forced re-education.
"Dear Brutal Dictator XI JINPING and the Chinese Government. Tibet belongs to the Tibetan people!" Kanter said in a message posted on Twitter, Facebook and Instagram.
"I stand with my Tibetan brothers and sisters, and I support their calls for Freedom," the 29-year-old added, next to a picture of sneakers adorned with Tibetan iconography and the slogan "Free Tibet".
The message accompanied a three-minute video of Kanter wearing a T-shirt of the Dalai Lama and criticising Chinese rule in the region.
Kanter wore the political sneakers on the sidelines of the Celtics' 138-134 double-overtime defeat to the New York Knicks on Wednesday night, a game he did not appear in.
Global brands including the NBA have in recent years been consumed by PR crises and faced financial repercussions in China after touching politically sensitive subjects.
Swiss-born and Turkey-raised, Kanter is a devout Muslim, and vocal in defense of various political causes.
He has previously angered the Turkish government of President Recep Tayyip Erdogan, who he has also dubbed a "dictator".
In more than 700 NBA appearances, he has also turned out for Utah, Oklahoma City, New York and Portland.