"It may be this month [or] next month," Rondo told reporters in San Francisco before the Celtics' morning shootaround in advance of Friday night's game against the Golden State Warriors. "It'll be before All-Star break."
The Celtics play their final game before the midseason break on Feb. 12, when the San Antonio Spurs visit TD Garden. Rondo remained noncommittal if his return might come before that point.
"It's just a feeling," he said, according to MassLive.com. "I'll probably just wake up that morning and play."
Rondo tore his right ACL in late January 2013 and underwent surgery in mid-February. He has patiently navigated his rehab but concedes it's hard not being on the floor.
"I don't even like to watch the game anymore," Rondo said, according to The Boston Globe. "It's frustrating. You see things that you just can't help. It's only a matter of what you can do from a vocal standpoint on the sidelines."
Rondo did note that he feels "10 times better" and "more confident, stronger, more explosive" based on the work he's done since being cleared to return to full-contact activities last month.
And Celtics first-year coach Brad Stevens noted that Rondo has looked good during situational game work during practice.
"In practice, when we have done 5-on-5 and he's been able to compete in that, he has really, really done well," said Stevens, according to MassLive.com. "And part of that is because not only does he have a feel for where he should be, he just gets everybody else in the right spots."
Stevens said before Friday's game that he has never spoken to Rondo or anybody in the organization about a specific return date and that the decision on Rondo's return will not be made by him. It will be solely up to team doctors and the point guard, Stevens said.
"It's not my call," the coach said. "Obviously the trainers, No. 1, to be able to clear him to do certain things, to clear him to play games, to clear him to practice. That's their job, and they do that well.
"And it's about him feeling ready in a number of ways. I can't lose sleep over things I can't control personally. I'm more concerned about him being healthy. I want him to be fully ready to go mentally, emotionally and physically. And when that time is right, we'll plug him right in."
Rondo has flirted with the idea of joining the Maine Red Claws of the D-League for practice or game reps. He suggested that's still a possibility after the Celtics return from a five-game West Coast trip that wraps up Saturday night in Portland.
Entering Friday, the Celtics (13-23) had lost six in a row and nine of their past 10 but remained only 1½ games back of a playoff spot in the Eastern Conference. They were five games back of the division-leading Toronto Raptors in the Atlantic and only a half-game in front of the basement-dwelling Philadelphia 76ers.
The Associated Press contributed to this report.