Jermaine O'Neal returns to Boston

MEMPHIS -- After seeking a second opinion Friday from the Miami doctors who treated him during his time with the Miami Heat, Boston Celtics center Jermaine O'Neal did not travel with the team to Memphis and instead planned to return to Boston, according to the team.

O'Neal, who is battling lingering left knee soreness, will not be available for Saturday's game against the Grizzlies. His departure leaves the Celtics with only 11 players as Boston prepares to wrap up a four-game road trip.

Before Thursday's game against the Heat in Miami, O'Neal stressed that he wanted to seek the opinion of doctors more familiar with his knee ailments and see if their diagnosis could help map out a definitive recovery plan.

"I'm going to get a second opinion, just a thing that a player should do," O'Neal said. "Obviously, I believe in our staff a lot, I support our doctors and we have some of the best doctors in the world. But I just want to get a different opinion, see if everybody's on the same page. This is the third time it's blown up on me, so I have to do something.

"Obviously, I'm new to the team. I know our doctors have checked over my records, but being [in Miami] for two years, they dealt with it and I didn't have any issues when I was here. [The knee] was strong, so I'm just kinda getting their opinion, then putting it with our doctors and getting them together for a conclusion on why the knee is blowing up the way it's blowing up."

O'Neal, who sat out the second half of Monday's loss in Dallas, experienced no improvement in the swollen knee despite two off-days before Thursday's tilt. He participated minimally in Boston's shootaround Thursday morning.

O'Neal said Boston team doctors have taken MRIs of his injury and have identified potential ailments, but he has been cryptic in revealing their diagnosis and the means of treating the knee thus far, suggesting only that he's had a "procedure" aimed at relieving the injury.

One of those concerns appears to be knee arthritis, a degenerative condition any NBA player is subject to from the wear-and-tear of the sport. But O'Neal also underwent surgery to repair torn meniscus cartilage in his left knee in April 2007 and missed 42 games the following season due to pain and swelling, making him somewhat more susceptible to the condition.

"This is the most swelling I've had since I tore my meniscus three or four years ago," O'Neal admitted Thursday. "I know the length of time it took to get back from [the meniscus] -- it took a while."

He's hoping to get a diagnosis of a more treatable ailment because it's virtually impossible to cure arthritis, short of a complete knee replacement. Also known as osteoarthritis, knee arthritis occurs when cartilage is worn away, leaving the bare bone exposed to the joint. Symptoms can come and go, but include stiffness in the knee and swelling of the joint, which appears to be consistent with what O'Neal is battling.

While he's mentioned arthritis only in the context of injuries that veteran players can encounter, O'Neal addressed that potential when asked about it before Thursday's game.

"I'm sure every player in [the Celtics' locker room] has that, I'm positive," said O'Neal, 32, who has been in the league for 14 years and has 869 regular-season games and 24,574 regular-season minutes gnawing at the tread on his tires. "I know that, if it is [arthritis], we have to figure out how to slow that down. I've never had a real issue unless it was injury -- the meniscus or whatever else might have made it swell. I'd almost rather have it be something fixable than something that's not."

Chris Forsberg is the Celtics reporter for ESPNBoston.com. Follow him on Twitter.