"If I'm watching the playoffs from home and it doesn't eat at me that I'm not playing, I'll know I'm done," O'Neal told the San Francisco Chronicle.
O'Neal, who opted to stay in Los Angeles after the Warriors' Game 7 loss to the Clippers instead of flying back with the team, will talk with his family and then determine if his body can take another season in the NBA.
He suffered a hyperextended right knee on what he called a "dirty play" by Glen Davis during Game 6 against the Clippers and played only three minutes in Game 7. He averaged 6.0 points and 3.4 rebounds during the series, after finishing with averages of 7.9 points and 5.5 rebounds during this season.
"It's been a fantastic run," O'Neal told the Chronicle. "You never picture your last game being one where you can't be effective in a Game 7. That's a tough pill to swallow."
The 35-year-old O'Neal has averaged 13.2 points and 7.2 points during his career.