On Friday, the NBA sent a memo to its teams explaining that they should be preparing to play games without fans in attendance as a result of the coronavirus outbreak, according to The Athletic's Shams Charania.
Per The New York Times' Marc Stein, they alerted teams to put together contingency plans in case "it were to become necessary to play a game with only essential staff present."
In recent days, sporting events around have started taking place without crowds.
As an example of the wide breadth of sporting events impacted, a list of contests being played without fans include the first two rounds of the NCAA Division III tournament at John Hopkins, preseason Nippon Professional Baseball, South Korean Basketball games and some Europa League soccer matches, among countless others.