In a statement Monday, the Rockets said Brown "had no prior knowledge of or interaction with the assailants."
He is expected to make a full recovery, according to the team.
The Rockets are in Miami for a Monday night matchup against the Heat. Brown is with the team but had previously been ruled out for the game due to a knee injury.
"Heart-wrenching. Rips your heart out,'' Houston coach Stephen Silas said before the game. "It's one of your guys, someone on your team that you care about, someone that you're with every day. As far as how I'm feeling and how the team is feeling, we're all just thankful, No. 1, that he's going to be OK -- and also down about what happened.''
It wasn't immediately known if any incident reports were filed with police. The NBA said it was gathering information on the incident and was hopeful Brown makes a full recovery.
Brown, 26, is in his first season in Houston, averaging 8.2 points and 4.4 rebounds in 51 games.
He had spent the previous three seasons with the Milwaukee Bucks, averaging 5.2 points and 3.1 rebounds.
While in Milwaukee, Brown was thrust into the national spotlight when he alleged that police officers targeted him outside a Walgreens store on Jan. 26, 2018. He alleged that Milwaukee officers targeted him because he is Black. They used a stun gun when he didn't immediately remove his hands from his pockets when ordered to while waiting for a parking citation.
Brown first filed a lawsuit against the city of Milwaukee in June 2018 after body-camera footage was released showing a police officer stepping on his ankle during the arrest while others mocked his potential civil rights complaint.
Brown reached a $750,000 settlement with the city in November.