(Associated Press)

The Sixers' Andrew Bynum said he's still feeling pain in his left knee after two-hour workouts on the court, adding that it “limits me from continuing to go” and that the pain might keep him from debuting by the end of the month, his targeted time to return.

Bynum said he's doing defensive slides, dunking and full-court work, though he hasn't begun 1-on-1 workouts or 3-on-3 scrimmages.

The injured center had said he wanted to return in February. He doesn't sound so optimistic about that now.

“I'm not sure,” Bynum said Monday, before the Sixers hosted the Los Angeles Clippers. “It's all going to depend on it we get a setback or not.”

Bynum said the pain he's experiencing does not produce swelling and the pain goes away by the next day.

“It's just not ready,” Bynum said.

He added: “I'm not really optimistic. When I get on the court, that's when I'll be ready. I'm trying as hard as I can. It would suck to play through pain, but sometimes you have to.”