LeBron James (right) described the Heat defense as "terrible." (Mike Ehrmann/Getty Images)

During the preseason, the Heat talked about avoiding a repeat of last season's slow start on the defensive end. The results haven't matched the rhetoric.

LeBron James identified defense as the main reason for the two-time defending champions' sluggish 4-3 start.

"It's simple. These first seven games, we're playing like s--- defensively," James said, according to ESPN.com. "It's that simple. We're not a sugarcoat team. We came in and got right down to it. We're terrible on defense, and we've got to change that."

The Heat entered Tuesday's game against Milwaukee ranked 25th in points allowed per possession, according to ESPN.com's figures, and 27th based on Basketball-Reference's defensive efficiency calculations. Miami is also 26th in field-goal defense (47.3 percent) and 21st in points allowed (100.9). Those numbers help explain why the Heat are only a game above .500 despite leading the NBA in offensive efficiency.

James' pointed comments came after the Heat allowed 111 points and 51.7 percent shooting to the Celtics, who won in Miami on Jeff Green's last-second three-pointer Saturday. LeBron said the Heat have played "unmotivated basketball" the first two weeks of the season.

"I don't know if it's going through the motions, guys are injured, a long season, short summer, I don't know what it is," James said, per the South Florida Sun Sentinel.

has made no secret

was unhappy finishing second

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Marc Gasol