The picture was posted for about 10 minutes Sunday afternoon on Snapchat, then was taken down.
"I apologize for the situation. It's clearly not what I was trying to do," he said.
Green said he knew instantly he made a mistake and took the photo down.
"It was a situation where it was meant to be a private message," Green said. "I kinda hit the wrong button and it sucks. It was meant to be private. We're all one click away from placing something in the wrong place, and I suffered from that this morning."
Green made his comments prior to Team USA's practice at the Toyota Center.
Immediately after the picture was removed, Green had tweeted:
Earlier in July, Green reached a plea agreement that will allow him to avoid jail time and reduced the charges he faced for allegedly slapping a Michigan State University football player and for a noise violation.
Green will pay a $500 fine and a $60 restitution fee for the incident. He was arrested July 10 in East Lansing, Michigan, after police saw him slap MSU player Jermaine Edmondson, who has since been released from MSU's team to play elsewhere. Edmondson's release was not related to the incident with Green, MSU officials said.
In June, Green was suspended for a game during the NBA Finals for hitting LeBron James in the groin.
"I'm in a great position in my life," Green said Sunday. "There's so many things going on in my world for me to sit and complain, 'I can't catch a break.' I'm living my dream.
"To say I can't catch a break I think that's disrespectful for everybody," he added. "How many people get to live their dreams? I'm not going to sit here and throw myself a pity party and say I can't catch a break. I'm fine. I get to joke around with these guys all day and get to do what I love for my country. I'm fine. I'm fine."