Morant will miss at least two games, according to the Grizzlies, who did not elaborate on why.
On social media, several people posted video clips showing Morant carrying what seemed to be a gun.
The Memphis Grizzlies announced on Saturday that standout guard Ja Morant would miss at least two games due to an investigation into a social media video in which Morant appeared to be holding a gun.
The Grizzlies did not respond quickly to questions about the social media post, Morant's absence, and whether he had been disciplined.
On Saturday, several people released video footage on social media that appeared to show Morant holding a gun and smiling in a nightclub in a live video on his Instagram account.
As of mid-Saturday morning, Morant's verified Instagram account had no live streams matching the snippets circulating on social media. By the afternoon, Morant's Instagram and Twitter accounts had been deactivated.
Morant, 23, issued a statement in which he accepted "full responsibility for my actions last night," without elaborating, and apologized for disappointing people.
"I'm going to take some time away to get help and work on learning better methods of dealing with stress and my overall well-being," Morant said in a statement posted on Twitter by Tandem, his agent.