LOS ANGELES – Kendrick Perkins went out and the Boston Celtics’ toughness went right along with him.

Perkins injured his right knee midway through the first quarter of Game 6 of the NBA finals on Tuesday night, and the Los Angeles Lakers capitalized by controlling the paint and the backboards after he left.

Los Angeles won 89-67 to force a Game 7 on Thursday night, and the Celtics will spend all the time until then hoping their starting center will be available.

Because without him, they were the weaker team, outrebounded 52-39 and getting outscored by more than a two-to-one difference on second-chance points.

Perkins lacks the importance of Boston’s Big Three or fellow starter Rajon Rondo, who has been perhaps the Celtics’ best player during their unlikely run to the NBA finals.

But he is crucial to the Celtics’ defensive schemes because he’s solid enough to play his man one-on-one, as Boston had him do against Orlando All-Star Dwight Howard in the last round, and a good help defender and rebounder.

That’s become even more important this season because Kevin Garnett can’t do the things he did two years ago, when he was the defensive player of the year and the quarterback of Boston’s defense.

Perkins was going for a rebound when he was fouled by Andrew Bynum with 5:30 remaining in the first quarter. Perkins quickly fell to the floor and remained there for a few minutes before a pair of teammates slowly helped him to the locker room for X-rays, which revealed a sprain.

The Lakers led by six when Perkins went out and easily added to their advantage, fearlessly attacking the rim for powerful dunks from such players as Shannon Brown and Jordan Farmar without a big body there to stop them — or make them pay for their audacity.

The Celtics have other big men, but starting Rasheed Wallace or Glen Davis weakens a bench that played such a key role in their Game 4 victory. Whatever situations they use Wallace in, he will have to be better than he was Tuesday, when he missed all seven shots and was 0 of 6 from 3-point range.

The fiery Perkins came into the finals with six technical fouls during the postseason, one away from an automatic suspension. So the Celtics have faced the fear all series of potentially being without their center.

They might have to go without him Thursday in the game that will determine their season.

They will have to be better and tougher than they were Tuesday.

 

RAJON RONDO might have had a very different NBA career if he had ended up on a team other than the Boston Celtics coming out of Kentucky.

Celtics Coach Doc Rivers credits Rondo’s development to being around veterans Kevin Garnett, Ray Allen and Paul Pierce.

“Most young guys come in the league, they don’t even know what a routine is,” Rivers said. “Where if you ask a veteran what he does on game day, he can probably tell you to the second every step that day until the game starts what he’s going to do.”

Now in his fourth season with the Celtics, Rondo had a triple- double in their Game 2 win against the Lakers, and he has the second-most in team playoff history with five, trailing Larry Bird, who had 10.

 

PHIL JACKSON knows how much offense the Lakers generate off Kobe Bryant. What he wants is the rest of his team to step up.

“There’s too much individual action,” he said. “There’s got to be more team play on the offensive end.”

Bryant took twice as many shots through the first five games of the finals as the next-highest player on the team, Pau Gasol.

“We looked for him too often, he didn’t get going and there was a need for the team to give him the basketball,” Jackson said about the Lakers’ Game 5 loss. “We talked about that in our pregame (Tuesday).”

 

BEFORE GOING on to star in the NBA finals, Kobe Bryant and Rajon Rondo took part in the Top 100 camp.

Eight players in this series are alumni of the NBA’s camp, which runs today through Sunday at the University of Virginia.

The camp gathers some of the top high school juniors and sophomores in the country.