Ozil has fallen out of favour under Unai Emery amid question marks over his attitude, with his body language regularly questioned by onlookers.
Keown told talkSPORT: "I feel at times he has been disdainful with his team-mates if he doesn't get the right ball.
"To be honest, if he was in our dressing room there were a few players who would have had him round the throat early on because of his body language."
Keown has urged the German playmaker to back-up his words and end what he branded an "embarrassing" situation for the club with their highest earner sat on the sidelines.
Keown added: "I was seriously worried for his immune system, the amount of games he missed through allegedly being ill, or a back injury.
"He has only been given another opportunity with Emery because it looks like he has started to work hard again.
"I believe he has been over-indulged in the past. It's embarrassing for the football club that he is not featuring.
"The manager has to get him back into the team but if his attitude drops again then big decisions need to be made."