The question when the Celtics brought in a player like Shaquille O’Neal, whose personality is as big as it is bankable, was how he would mesh with Kevin Garnett, who’s completely comfortable being crabby on the court. There was this idea that Shaq somehow would lighten Garnett’s mood.

Then the Celtics lost back-to-back games, and Garnett was his typically maniacal self.

“I think Kevin’s always going to be Kevin,’’ coach Doc Rivers said. “You could put Robin Williams and Eddie Murphy next to Kevin and he’s going to be Kevin Garnett.’’

But so far, the combination has worked. Last night, they posted double-doubles in the same game for the first time this season. Garnett (17 points, 11 rebounds) put up his sixth double-double of the season. O’Neal (13 points, 11 rebounds) went for his first.

“I think it’s a relationship of respect,’’ O’Neal said. “We’ve both had many battles over the years. We both have seen what each other can do over the years. So we basically can say anything to each other.’’

O’Neal’s presence on the floor takes some of the burden off Garnett, and vice versa.

“Being that they’ve got to respect him, it leaves a lot of room for me,’’ O’Neal said. “And since they respect me, it’s a lot more room for him. So we’re going to use each other and I think it’s a good fit.’’

Garnett said, “Shaq is like a paradise, man. You ever wash your sheets and then when you go out, you hang them out and when the sun dries them you smell your sheets? That’s what Shaq is.’’

Rondo out again The Celtics continued to be cautious with Rajon Rondo, letting the point guard rest for the second straight game to heal the left hamstring he strained Friday night against Oklahoma City.

Rondo tested the hamstring last night, hoping he could play after sitting out against Toronto, but Rivers consulted with trainer Eddie Lacerte and decided to keep Rondo out of the lineup. Rivers was uncertain whether Rondo would be ready tomorrow against the Nets.

“If it’s an ankle, you always push the envelope,’’ Rivers said. “If they say they can play, you usually let them play. But if it’s a hamstring, I don’t even consult with Rondo on a hamstring. It’s straight what Eddie says.’

“The player has very little input with hamstring injuries because they all think they can play. Then they get out and they tear it, and now you’re out for the year. So I don’t think I’ve asked Rondo one question about his hamstring.’’

Rondo missed time last January with a hamstring injury.

“There’s just no benefit of playing one of your key guys, or any guy, getting them injured, and now they’re out for the season or longer than they should be,’’ Rivers said. “I would rather take the approach of doing without him early right now, and in a lot of ways it could help your team in the long run.’’