Two centers of medical attention

LOS ANGELES – Big men. Big problems.

As if Game 7 wasn't big enough, the Lakers and Celtics have some big injury issues for Thursday night, involving their respective centers.

The Celtics' Kendrick Perkins went down to a sprained knee in the first quarter last night, while the Lakers' Andrew Bynum had to leave the game with more trouble for the right knee that has been hampered throughout the Finals because of a torn cartilage.

Perkins was the Celtics' top rebounder before Game 6 and is their enforcer in the paint. When asked if he'll have Perkins for Game 7, Doc Rivers said, "It's doesn't look great, but I don't know.''

Here's what Rivers does know: The Celtics will miss his presence if Perkins can't go or is limited.

"He's a guy who cleans the paint up and not having him in there made the Lakers awful long'' Rivers said. "He gives us great spirit, a lot of toughness and size. It'd be tough if he can't play.''

Bynum's setback was the just the latest, as he's played the entire playoff run on a bum knee. Last night he gave Phil Jackson only 15:53.

"He had some tightness in the back of his leg,'' Jackson said. "He just said, "You've got to take me out, I can't run.' And it was obvious that he couldn't. He had some swelling in the back of the leg.''

Bynum had fluid drained from his knee last Friday, two days before Game 5. As for Game 7, Jackson was worried, as he should be. Without Bynum, or if he's limited, the Lakers lose their muscle inside and a defensive presence in the paint.

"Of course it concerns us,'' Jackson said. "Both teams are playing without players at this time. You just have to gut it through at this time of the season.''

Turning the tables

Kobe Bryant knows how the Lakers crushed the Celtics in Game 6.

By doing what they did not do in Game 5.

The Lakers beat the Celtics at their own game, blanketing Boston with some of the best defense they've played in the postseason. The 67 points the Celtics scored tied a Finals low, and was 25 off their postseason average, and 25 off their total in Game 5.

Boston's 33-percent shooting was a far cry from the 56-percent figure they made in Game 5 Sunday when the Celtics took a 3-2 series lead.

"We didn't execute well defensively,'' Bryant said, remembering Game 5, when the Lakers allowed Boston to score on 12 of its first 13 possessions of the third quarter, negating Bryant's great run of 19 straight points. "We just missed a lot of coverages. But we made the adjustments. We kept them out of the middle. We kept them out of the paint. We did a good job on the boards.''

The Lakers dominated the glass, 52-39. They limited Boston to six second-chance points. And they allowed only nine fast-break points.

"Our defense was good, our rebounding was better,'' Phil Jackson said.