NBA

Billups says rested Celtics will have hands full with Knicks

The Celtics rested their four big guns Monday night, lost to the lowly Wizards and officially inherited the Knicks in the first round, likely beginning Sunday in Beantown. Chauncey Billups wonders if the Celtics may one day regret it.

Be careful what you rest for.

“Yeah, I think we are certainly the most dangerous first-round team in the NBA,” said Billups, who scored 10 to go with eight assists in last night’s 103-90 loss to the Bulls at the Garden. “We got a lot of weapons and we can move the scoreboard. Our defense has gotten a lot better. We’re going to be a tough team, a tough out.”

The “Blood Feud” between the Knicks and Celtics resumes Sunday after a 21-year postseason hiatus. The defending Eastern Conference champions are the distinct favorites, but the Knicks are the crazy wildcard whose Big Apple 3 have struck fear around the NBA.

Before last night’s game, owner James Dolan, architect of the Carmelo Anthony blockbuster, was in a chipper mood, shaking Knicks president Donnie Walsh’s hand briskly 90 minutes before tip-off as they chatted. Walsh said his team can’t be considered arch-rivals of the Celtics until it knocks them off in the playoffs.

“We’re two of the longest-tenured franchises, but those rivalries are engendered by the teams playing right now,” Walsh said. “There was one rivalry way back. But the rivalry will have to come in the playoffs. For us, we have to beat them. We have to beat them once to be considered that.”

Tonight, the Knicks, Celtics, ironically, face each other in their regular-season finale at the new Boston Garden in what equates to the weigh-in of a heavyweight title fight. Both clubs plan to rest their starters preparing for Round 1 this weekend.

Though the Celtics stumbled down the stretch since the bizarre Kendrick Perkins trade, going 9-11 in their last 20, this is battle-tested club that won all three games vs. the Knicks this season, including their “bloodbath” 96-86 Garden victory March 21.

Kevin Garnett, Paul Pierce, Rajon Rondo and Ray Allen know when it’s money time.

“They’re veterans and they’re champions,” Knicks coach Mike D’Antoni said. “That’s the biggest concern. Their mentality is probably better than anybody’s.”

Anthony spilled blood on the Garden court in his first match vs. Boston as a member of the Knicks, needed five stitches and still has the scar to show for it. And he’s expecting nothing less when the Knick and Celtics begin their 14th playoff series.

“Brutal battles, man,” said the Brooklyn-born Anthony, reflecting on the Celtics-Knicks history. “Wars. It’s going to be a very intense, high-energy series. They got something to prove. We have something to prove. I’m pretty sure it’s going to be a battle. It’s going to be crazy. We just have to keep our composure. It’s going to be a very physical series. That’s the way they play.”

And this is why Anthony wanted New York, to team up with Stoudemire and go to war in the postseason.

“Once I got here, the playoffs was my No. 1 priority,” said Anthony, who’s won consecutive Player of the Week awards. “I can only imagine how that atmosphere is going to be — in Boston, in New York. New York’s been waiting for a long, long time. We’re excited about to step on the court and play playoff basketball.”

The Knicks, who had won seven straight before last night’s loss, and are starting to gel.

“I always felt confident even when I first got here,” said Anthony, who has seen the club recover from a 1-9 stretch. “It just so happens it’s clicking right now for us, to win seven straight going down the stretch into the playoffs. It’s a big momentum swing and confidence booster for us.”

But these are the Celtics. Five of the seven Knicks wins during the streak have come against Eastern dregs.

“They’re one of the top defensive teams in the league,” ex-Celtic Billy Walker said. ‘We’re going to have to go out and go on the attack. If you let the defense attack you, it’s going to be a long night.”

The Celtics have been ripped in the Boston media for sitting their top four studs Monday night in Washington and for their mediocre recent play.

“They said the same thing about them last year,” Walker said. “They’re struggling and they made it all the way back to the NBA Finals. That means nothing. Playoffs is whole different animal.”

marc.berman@nypost.com