Rondo made the comments after Boston's final preseason game, a 101-97 victory over the Brooklyn Nets.
Rondo underwent surgery in February to repair a partially torn ACL and hasn't played since. He said he was fitted for a brace and hopes to be allowed to return to full contact activities.
The Celtics open the regular season on October 30 with a road game against the Toronto Raptors.
"I'm feeling great, working out everyday. I’m able to do more as far as compound workouts, versus me just doing one workout per day," Rondo said, according to ESPN.com. "I’m doing more on my leg and I’m able to handle it. It’s getting better, getting stronger every day." "I’ll know when it’s right," said Rondo. "Everybody is different, each injury is different... For me, when I come back, I won’t come back unless I know I’m myself again."