A contingent from Hanscom Air Force Base presented the Celtics with a flag before yesterday’s practice, and Kevin Garnett — who has become something of a ghost — slipped out of the locker room to take part in the ceremony.

This, as it turned out, was a sign of better things to come. Doc Rivers was careful not to make a definitive statement, but the Celtics coach did allow that Garnett could possibly return from an inflamed left ankle for Sunday’s home game against Washington.

“I think he’ll be back, maybe as early as Sunday, but we still don’t know that,” said Rivers. “He’s still doing all of the running, he’ll do some court stuff without the team, and he’ll probably take part in shootaround (today), but I won’t play him (tonight against Cleveland). The ankle feels good.”

For a Celtics team that has struggled the last seven games without Garnett, the center’s presence couldn’t be more overdue.

“It’s good to see him around, rehabbing, coming out here and sweating,” said Jason Terry. “Everything with what he has said has been positive about coming back.”

The flag, by the way, was flown from a C-130 cargo plane over Afghanistan on Veterans Day last year during Operation Enduring Freedom. Rivers had the entire team, including Rajon Rondo and Jared Sullinger, pose for pictures with the airmen.

Papa Pierce glowing

Paul Pierce, whose wife Julie gave birth to their third child (Prince Paul Pierce) on Tuesday night, has a definite athletic plan for his first son. It has to do with the one position in baseball that guarantees a long career.

“I want to put a baseball in his hand, his left hand,” said Pierce, who admits that after two daughters and one son, he’s a much-changed man.

“It’s definitely changed me,” he said. “It’s helped me understand you have people depending on you. In everyday life you’re much more mature about the decisions you make. . . . I just want him to grow up, be a smart kid, get into the books. There’s nothing like it. I’ve had two baby girls and now a baby boy, it’s one of the best feelings in the world, seeing a life. I can’t even explain it.”