"It was definitely dumb on my part," he said. "It's something that I am embarrassed about. [I'm] still dealing with the league and the team. But I'm not happy about it at all."
TMZ released video Thursday that showed a man it identified as Okafor verbally sparring with several individuals. A scuffle broke out, and the man identified as Okafor is seen punching a man.
Okafor, who was with teammate Christian Wood at the time, said he spoke to Sixers coach Brett Brown about the incident Thursday. The 76ers released a statement Thursday evening saying they were aware of the report and working to gather additional information. An NBA spokesman also said Friday that the league was aware and looking into the matter.
Okafor was expected to play in the Sixers' game Friday night against the Houston Rockets.
Meanwhile, Boston police said Friday they do not plan to investigate the incident unless someone involved comes forward to say they were the victim of a crime.
Officer James Kenneally said police responded to reports of a fight outside a Boston nightclub Wednesday night. But Kenneally said the participants were gone by the time officers arrived and nobody was arrested or charged.
"Apparently, they said: 'The 76ers suck and you guys are all losers. You'll never win a game,'" a source close to Okafor told ESPN's Jeff Goodman of the altercation.
"I was around the corner when it happened. I saw [Okafor] a minute after he knocked the dude out," the source said. "I think the guy was just talking s---. Saying the Sixers suck."
The Sixers lost 84-80 to the Celtics earlier Wednesday evening. Okafor, the No. 3 overall pick in the 2015 draft, had 19 points and nine rebounds in the loss. He is averaging a team-high 18.4 points with 8.1 rebounds per game.
The Sixers (0-16) have lost 26 straight games dating to last season and are the first team in NBA history to start 0-16 in consecutive seasons.
Information from ESPN's Marc Stein and The Associated Press was used in this report.