Celtics fans will shudder when they learn Kevin Garnett has inflammation in one of his joints, but president of basketball operations Danny Ainge insisted yesterday that, while the Hall of Famer-in-waiting could miss two weeks, this latest injury is not a long-term proposition.

A second look at an MRI on Garnett’s left foot and ankle revealed inflammation.

“So take a couple of Advil and give it some rest,” Ainge said. “It’s not an ankle sprain. There’s inflammation.”

Garnett missed the 2009 playoffs with a sore knee that, upon surgery, was found to be caused by a larger than expected bone spur. The Celtics are saying this situation is different, and not just because it’s an ankle rather than a knee.

“I think it happened in the New Orleans game,” Ainge said, referring to last Wednesday’s road loss to the Hornets.

Garnett tried to play through the discomfort two nights later in Dallas when the C’s lost to the Mavericks, but was held out of Saturday’s loss to the Grizzlies in the trip finale in Memphis.

“It was just sore. A lot of things can cause inflammation,” Ainge said. “Everybody has a little inflammation at this time of the year. We need to get him fresh anyway.”

As for when Garnett will be back in the lineup, the Celtics are clearly thinking in terms of the playoffs, which are just 13 more regular-season games away.

“I think it’s not longer than three weeks,” Ainge said of how long Garnett could be out. “It could be a week. I’ll guess two weeks because we want to make sure he’s really ready.”

That philosophy is guiding the Celts, even as they jostle for playoff seeding.

“My feeling is we’ve got to get there, and we’ve got to be healthy,” Ainge said of the postseason.

Speaking to the media before the second look at Garnett’s MRI had been completed, coach Doc Rivers echoed the theme.