BOSTON – There’s something about the Boston Celtics’ 14-game winning streak that doesn’t seem quite right to Coach Doc Rivers.

Point guard Rajon Rondo, after getting off to the best start of his career, has missed six of the 14 wins. Backup Delonte West missed the last 12. Shaquille O’Neal sat out four. Jermaine O’Neal hasn’t played since the winning streak began. And Kendrick Perkins, the starting center on last season’s Eastern Conference champions, hasn’t gotten on the floor all season.

“Usually when you’re on a winning streak, everybody’s healthy, everybody’s playing well and you’re rolling,” Rivers said Wednesday night after the Celtics beat the Philadelphia 76ers 84-80 for their 14th straight win. “You could make the case it’s the opposite with us.”

Ray Allen scored 22 points and Paul Pierce recovered after missing his first seven shots to score 11 with four key baskets in the second half. Shaquille O’Neal had 13 points and nine rebounds, but missed two free throws with 1:02 left and Boston nursing a two-point lead.

That gave Philadelphia two chances to tie it, but Andre Iguodala slipped and turned the ball over the first time, then had his shot blocked by Kevin Garnett the next.

Allen hit a pair of free throws with 5.6 seconds left to ice it.

“We’ve won games in the 100s; we’ve won games in the 80s. And we’re just finding ways to grind it out because we don’t have the healthy bodies,” said Pierce, who finished 4 of 15 from the floor. “You don’t know who’s going to be in there night-in and night-out.”

Elton Brand had 16 points and 12 rebounds, and Jrue Holiday scored 15 points for Philadelphia, which was coming off its worst loss in three years — a 45-point loss Tuesday night to the Chicago Bulls.

“I couldn’t be more proud of them,” Sixers Coach Doug Collins said. “(Tuesday) night was such an aberration. Our guys compete every night, and for them to come out and play the Celtics like they did, they showed who they are. That’s who I know they are.”

The Sixers led with five minutes left before Pierce stole the ball near midcourt and took it in for a dunk. It was 80-78 when Pierce hit a 19-footer, just his fourth basket of the game. Brand made a short jumper, then fouled out when he pulled O’Neal down to keep him from scoring an easy layup.

O’Neal missed both foul shots, but Iguodala slipped near the lane and Garnett came away with the ball. After Boston failed to score, Iguodala went to the basket but Garnett tipped the shot and Pierce came away with the rebound.

“We expected their best due to how they played (Tuesday) night, and how they got beat,” Garnett said. “So we were prepared for a dogfight. We don’t like ’em. But hey, we’ll suit up for them either way.”

The Celtics haven’t lost since Nov. 21, the second game of their only two-game losing streak of the season. Their 14-game winning streak matches the fifth-longest in the history of the NBA’s most-decorated franchise, and ties the third-longest in 46 years.

The 2007-08 team, which won Boston’s 17th NBA title, won a franchise-record 19 straight.

Lou Williams scored 12 points and Tony Battie, had 10 for Philadelphia.

NOTES: Celtics Coach Doc Rivers said he expects Jermaine O’Neal to be ready for Saturday’s Christmas Day game in Orlando. O’Neal hasn’t played since Nov. 8 because of a sore left knee. Celtics point guard Nate Robinson left late in the first quarter to get his ankle retaped, the team said. In the second half, he had ice on his right thigh. The Celtics were called for two technical fouls in the third quarter, on Garnett and Pierce, for complaining about calls.