Jermaine O’Neal has guaranteed that he’ll be back on the floor this week for the Celtics, returning to game action after six weeks away with a knee injury.

But will it be Wednesday night, when the C’s take on the Philadelphia 76ers at the TD Garden, or Saturday, when they head to Orlando for their Christmas Day showdown with the Magic? On that subject, the veteran big man is hedging his bets.

“I’m feeling OK,” O’Neal said after practice Tuesday. “Still trying to get stuff together. We haven’t really decided yet, but I’d say it’s a 50-50 chance still that I play [Wednesday].”

O’Neal practiced with the team for a second time on Tuesday, getting in more full-contact work than he had at his first session on Saturday afternoon. He’s inching closer to game shape, and the team is closely monitoring his condition as he prepares to play again.

“My body’s going to be a little sore because I haven’t been out there in a month and a half,” O’Neal said. “But there’s a difference between soreness and pain. Right now I’m just a little sore. But this is who I am right now. This is what God has given me. You deal with it, and you move forward.”

O’Neal has had ongoing conversations with trainer Ed Lacerte since Nov. 8, when he asked out of the Celtics’ loss to the Mavs at halftime with knee soreness. He says that he and the training staff have been on the same page all along, and there’s been very little conflict over his return schedule.

“It’s always mutual,” he said. “You talk about what’s going on and how I’m feeling, what their plan is and what my plan is, and come to an agreement. We’ll see how it goes.”

O’Neal has played in seven games for the Celtics this season, starting five of them. He’s averaging 5.6 points, 3.6 rebounds and 1.4 blocks in 17.7 minutes per contest. He’s hoping that come Wednesday, he can make a contribution again.

“It would be good to get back out there,” he said. “It’s been a while. It’s been almost two months since I’ve played a game. Sometimes, you just get tired of watching and cheering — you want to get out there and play ball.”