Heat coach Erik Spoelstra is rarely sarcastic during pregame news conferences. On Wednesday, he momentarily stepped out of character and offered a touch of his personality to shine through.

Earlier Wednesday morning, forward LeBron James tried to offer a possible reason why the Heat has had trouble rebounding. James suggested that rebounding is a “knack” and that “some guys have it; some guys don’t.”

“As a collective group, we don’t have it right now,” James said.

The Heat has been outrebounded in two of its last three games, including being outrebounded by Orlando 50-33 on New Year’s Eve. The Magic had 24 second-chance points and the Heat had 10.

Chris Bosh didn’t have the “knack” against Orlando, apparently. He had four rebounds while his Magic counterpart, center Nikola Vucevic, had 29.

Whether it’s rebounding, scoring or any other aspect of basketball, coaches, as a general rule, do not endorse, espouse or subscribe to “knack” theories. Spoelstra politely digested a second-hand report of everything James said about rebounding after Wednesday morning’s shootaround and quipped, “It’s interesting how sometimes we have the knack.”

For the season, the Heat is being outrebounded by an average of 41.0 to 38.8. Aside from James, who is playing at an otherworldly level, the Heat has been inconsistent under the glass.

Interestingly enough, in the two games the Heat grossly lost the rebounding battle in the past two weeks (Minnesota, minus-29 rebounding; Orlando, minus-17), the Heat won the games.

“We understand,” Spoelstra said. “We have to be a group rebounding team. We’re not going to have, typically, one guy eat up all the rebounds. On a given night, it’s going to have to be guys making rotations, finishing rotations, our perimeter players having to be blocking, other guys having to sacrifice and block out like a Shane Battier does as well as any in this league.

“And then, if you can’t get it, it’s got to be tipped to someone else. All five guys have to be involved. When we’re not. When one guy is taking a little mini-vacation, it hurts us.”

Bosh wasn’t himself against the Magic, and it nearly cost the Heat a victory against a depleted team. Orlando was missing several starters.

“It’s something that has been a concern,” Bosh said. “Guys are getting second-chance points. Teams are bigger than us. A lot of times we’re rotating away from the basket and teams are taking advantage of that, plain and simple. We’re going to have to figure out a way to fix it.”

James pointed to the Heat’s lack of size as well.

The team’s largest player, Dexter Pittman, was recently sent to the D-League.

Another option, little-used reserve Josh Harrellson, played 18 minutes during the Heat’s loss to the Bucks, but had just two rebounds.

“We don’t have a dominant rebounder,” said James, who leads the team with 8.4 rebounds per game.

“Collectively, we’ve got to try to help rebound with one another. Right now, we don’t have the size, the athleticism to go up there and dominate a rebounding game.

“We’re trying to collectively do it together, try not to give them second-chance points. We’re getting killed in that, too.”

ROAD WOES

The Heat owns the best winning percentage in the East, but is only 7-6 on the road. Miami went 2-2 on its recent four-game trip. Over the next 14 games, the Heat plays 10 games on the road.

“It’s something we’re going to have to get better at,” Spoelstra said of playing away from AmericanAirlines Arena. “Like it or not, this team has responded to challenges and that will be our next challenge. But we’ll deal with that when we get there. We’re not necessarily happy with how the road trip went. … But we have a three-game road stand we have to take care of first before we venture out west, and we want to make the most of these games and gain a little momentum and then address that challenge that we’re all well aware of.”