Lance Stephenson gave a choke sign at LeBron James after the latter missed a technical foul during the third quarter of Game 3.
"I was wrong and disrespectful to my teammates, the Miami Heat and their organization," Stephenson told NBA.com on Saturday. "I'm sorry that I did that. It was very disrespectful.
"(I) try to talk to other players, but in a good way. Get them off their game a little bit but not being disrespectful. I just got out of hand one time, and I'll never do it again."
James said he hadn't seen tape of the incident.
"Lance Stephenson? You want a quote about Lance Stephenson?" James said. "I'm not even going to give him the time. Knock it off."