Ozil's future at the Emirates Stadiums has once again been put in doubt after he was left out of the last three match-day squads despite being fit.
There have been reports that Ozil's attitude has contributed to the reported falling out with Unai Emery, and Keown claims the players in the dressing room during his time would not stand for that.
"I feel at times he has been disdainful with his team-mates if he doesn't get the right ball," Keown told TalkSPORT.
"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."
He 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."