Last week, NBA players began arriving in Orlando, Florida where they are being kept in a bubble as they wait to resume the season on July 31 at Walt Disney World Resort. 

But New Orleans Pelicans star forward Zion Williamson suddenly left the campus.

According to a statement from the Pelicans, Williamson had to attend to "an urgent family medical matter" and will rejoin the team at a later date. 

According to a tweet from New York Times NBA reporter Marc Stein, Pelicans head coach Alvin Gentry said he does not know when Williamson will return to Orlando, Florida.

Attempting to launch the season in the “NBA bubble” has gotten to a rocky start. After testing positive for COVID-19, Houston Rockets star Russell Westbrook has not arrived and it’s not clear when he will join his team in Florida, where the coronavirus is surging.  

Several other players have opted out including the Los Angeles Lakers’ Avery Bradley and Wilson Bradley of the Brooklyn Nets.