Celtics general manager Danny Ainge confirmed Monday that Garnett will be out for Tuesday’s game against the Knicks.
“Take a couple of Advil and give it some rest,” Ainge said. “Could he play [Tuesday]? Yeah but we’re not playing him [Tuesday]. The time frame, I don’t know but it’s not an ankle sprain but there’s inflammation in the ankle, sort of like an ankle sprain in unpredictability. So I think that it’s not longer than three weeks or it could be a week. I’ll guess two weeks just because we want to make sure he’s really ready. We need to get him fresh anyway.”
Doc Rivers  said Garnett aggravated the injury against the Mavericks and the discomfort forced him to miss Saturday’s game in Memphis. He was sent back to Boston for an MRI.
In the meantime, Rivers said it’s likely that Garnett will miss at least “four to five games” with the injury.
“I think we’ll know more later,” Rivers said, referring to the MRI. “I would say doubtful for [Tuesday] but we’ll know more later. I don’t think Kevin is playing [Tuesday]. I’m almost positive of that but then what we want to make sure is that he’s going to be good soon.
“At the end of the day, I want him right, not half-right.”
Rivers said he doesn’t expect this to be a season-ending ailment.
“But can he miss four or five games? Yeah that’s probably possible,” Rivers said. “I don’t know that but to me [season-ending] is not a concern. He hurt his foot in that Dallas game. [It’s not season-ending] unless something crazy happens in the MRI that I can tell you the first look, they didn’t see that. At the end of the day, he may miss some games.
“We’re going to err on the right side, whatever they decide. If they give me an option of you can play him every third game or give him two weeks rest, I can tell you right now I am going to say two weeks rest, if it’s my decision.”
Ainge later confirmed Rivers’ estimate, telling reporters at practice that the results of the MRI along with consultation with the team’s medical staff indicate that he’ll likely miss two weeks.
“I’ll guess two weeks, just because we want to make sure he’s really ready” said Ainge, who added that he thought Garnett originally injured the ankle against New Orleans last Wednesday.
“I think it happened in New Orleans game, it was just sore, just inflammation. A lot of things can cause inflammation. I think everyone has a little bit of inflammation this time of year. KG, we need to get him fresh anyway.”
On the bright side, Courtney Lee  is expected to return from his sprained left ankle suffered in the final minute of Friday’s loss in Dallas.
Neither player took part in Monday’s practice, which included just 10 healthy Celtics.
Rivers said the Celtics will be forced to go with a smaller lineup that he says includes “no point guards” while the Knicks feature a lineup with two point guards in Iman Shumpert and Raymond Felton , with Jason Kidd  off the bench.
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