Jefferson out

Celtics forward Al Jefferson underwent an emergency appendectomy this afternoon, according to Celtics executive director of basketball operations Danny Ainge.

Jefferson experienced severe stomach pain overnight and attended this morning's shootaround at Health Point in Waltham, but upon arrival, trainer Ed Lacerte sent Jefferson immediately to a hospital.

Jefferson, 21, was taken to New England Baptist Hospital in Boston where the surgery was performed, said team spokesman Jeff Twiss.

"I don't think that it's a major setback," said Ainge. "It's a minor setback for Al. We feel like he'll 100 percent in two or three weeks. That's why we have a 15-man roster."

This is another setback for Jefferson, who is hoping to have a breakout season after suffering a pair of ankle injuries last season and undergoing surgery Aug. 3.

In three games this season, Jefferson is averaging 11.3 points and 7.0 rebounds in 26.7 minutes per game. He recorded his first double-double of the season, scoring 11 points and grabbing 10 rebounds, against the Detroit Pistons on Nov. 3.