The Philadelphia 76ers say prized offseason acquisition Andrew Bynum will be out at least five more weeks and probably longer because of continuing complications with his right knee.

It is the third time since September that the Sixers have pushed back Bynum's return date.

Bynum had a fresh MRI and saw his personal knee specialist in New York last week. The Sixers now hope he will be cleared to return to basketball activities by Dec. 10.

"It's better than when it started, it's just not quite there yet," Bynum said. "It's not where I want it to be."

But the team said Bynum would then need an additional one to four weeks of training and conditioning, which means his anticipated Sixers debut may be on hold until January.

The Sixers are off to a 4-2 start without Bynum and have been without Jason Richardson because of an ankle injury for the past five games. Richardson was the other player Philadelphia received in the Bynum trade.

"We know the Sixers fans are eager to see Andrew Bynum play and shine," Sixers general manager Tony DiLeo said in a statement. "We also know no one is more eager to see Andrew play for the Sixers than Andrew himself. He fully realizes the key contribution he can make to the team. Hopefully, that day is coming soon."

The "hopefully" part is telling. It has become clear that while the team has been publicly optimistic and patient, it simply is not sure when the franchise center will get into a game.

The Sixers already have faced some criticism for trading away All-Star Andre Iguodala, young prospects Nikola Vucevic and Moe Harkless and a future first-round pick to get Bynum.

The decision is further complicated because Bynum, who's had surgeries on both knees and just turned 25 years old, is in the final year of his contract.

The team was hoping Bynum would continue to play at an All-Star level and prove he was healthy enough to be worth a long-term deal. With what the Sixers gave up to acquire Bynum, the team is already deeply invested in him.

Bynum announced in May, while he was still a member of the Los Angeles Lakers, that he was going to Germany in September for the popular Orthokine blood-spinning treatment. He waited until then, so the plan went, so the effects of the treatment could be maximized for the start of training camp in October.

Instead, however, the Sixers announced before training camp that Bynum needed to delay his return to allow the effects of the Orthokine treatment to work.

The bone bruise has since further complicated matters, causing the team to push the return date from training camp to the regular season and now possibly to midseason.

The Sixers did say they were optimistic because Bynum has been cleared for low-impact exercise and that by next week he may start work on an underwater treadmill.

"As far as getting better, I think this is the way I need to handle it," Bynum said. "It's tough. I want to get out there, I want to play. It's just a roller coaster. Obviously, missing games is not good. I want to be out there, I want to be there with my teammates."

Information from The Associated Press was used in this report.