LEVELAND – LeBron James’ famed right elbow won’t be the only one drawing attention.

Bitter enemies, the Boston Celtics and Cleveland Cavaliers are about to exchange elbows, shoves, insults and baskets in the NBA playoffs.

This reunion won’t be peaceful.

“We don’t like them, they don’t like us,” Cavaliers guard Mo Williams said. “It’s obvious.”

It’s on. Again.

For the second time in three years, the Cavaliers and Celtics will meet in the Eastern Conference semifinals, renewing a sweltering rivalry that has grown with intensity and will be ratcheted up to a new extreme when the clubs open the best-of-seven series tonight beneath a fire-spewing scoreboard inside Quicken Loans Arena.

Forget the buzzer.

Maybe a ring-side bell would be better to signal the end of each quarter.

“It’s going to be a good heavyweight fight,” Boston’s Paul Pierce said.

The Celtics and Cavs, who played a knock-down-drag-out series won by Boston in seven games two years ago, have been pummeling each other for some time.

A few years back, Pierce spit in the direction of Cleveland’s bench during an exhibition game. Last October, the teams got into a minor fracas during a preseason game in Columbus, Ohio, when Mo Williams retaliated with an elbow after being flung to the floor by Celtics forward Shelden Williams, who just happens to be the brother-in-law of Cleveland forward Anthony Parker.

Even James’ mom, Gloria, once got into it with Pierce, screaming at him after he wrapped up her baby boy on a breakaway dunk during the 2008 playoffs.

Tempers flared during the team’s previous meeting on April 4. Down by 22 points in the third quarter, the Cavaliers stormed back before losing 117-113 in a game that featured six technical fouls, the ejection of Cavs Coach Mike Brown and some animated, R-rated trash talk between James and Boston’s Kevin Garnett and Tony Allen.

“They do a lot of talking,” James said. “At some point they back it up, too. We’re looking forward to it. … It’s going to be a really fun, really physical series.”

James, who will accept his second straight MVP trophy on Sunday in Akron between Games 1 and 2, is entering the series with an injured right elbow that he says has been bothering him on and off for weeks. An MRI exam revealed a sprain and bone bruise, and James will wear a padded, protective sleeve to help absorb any contact.

On Friday, he didn’t seem bothered by the elbow while shooting mid-range jumpers during the portion of Cleveland’s practice that was open to the media.

“I figure this,” Pierce said, “LeBron with a bad elbow is still better than 95 percent of the league. So it doesn’t matter.”

Two years removed from their 17th NBA title, the Celtics are coming in as healthy as they’ve been in months and with renewed confidence after steamrolling through Miami in the first round.

Boston’s depth and defense were too much for the Heat, whose only win came when Dwyane Wade scored 46 in the playoff game of his career.

James and the Cavaliers present many more problems.

“LeBron’s a different beast,” Garnett said. “He’s obviously with a better cast than D-Wade.”

James has never had more help. Two years ago, he pushed the Celtics to a Game 7 without Williams or Shaquille O’Neal or Antawn Jamison, who has become Cleveland’s No. 2 option on offense.

Jamison was acquired in a deadline trade from Washington, and it didn’t take him long to appreciate the extent of the Cavs-Celtics feud.

His fourth game with Cleveland was in Boston on Feb. 25, when O’Neal sustained a torn thumb ligament on a block by Celtics center Glen Davis. O’Neal later underwent surgery and the injury took on added life when TV replays appeared to show Davis grabbing and twisting Shaq’s thumb.

O’Neal doesn’t think Davis tried to intentionally hurt him and said he’s not drawing any extra motivation because the Celtics are next on Cleveland’s climb toward a first title.

“The only incentive I’m worried about is the final goal,” O’Neal said.

“We know they’re a tough team. We know they’re chasing the same thing that we’re chasing. We just have to keep our heads, keep our composure and do what we’re supposed to do.”