Cleveland ? The Cavaliers have begun their push for the NBA playoffs — backward.

Six straight defeats have erased much of what Cleveland accomplished in the first half of the season, when it led the Central Division and played like a team on the verge of becoming a winner.

But now, in addition to losing games, the Cavaliers are losing confidence.

“I don’t see the fire, the intensity, the passion, all the things we’ve had at one time we’ve lost,” coach Paul Silas said Sunday night after a 102-82 loss to the Miami Heat. “They have to do some soul-searching. Either we’re going to pick it up or chuck it in.”

Maybe Silas should have seen this coming.

After all, the Cavs’ surprisingly strong start was aided by a favorable schedule, the Indiana-Detroit brawl that slowed those Eastern Conference powers and the dramatic one-year improvement of LeBron James.

The Cavaliers are 8-0 against expansion Charlotte and Atlanta and 14-0 overall against Golden State, Utah, New Orleans and Toronto — all last-place teams. Against the rest of the league, Cleveland is 17-27.

In the past week, the Cavaliers have been exposed at home by San Antonio, Seattle and Miami. The Heat won with ease, pulling away in the second half despite getting limited time from Shaquille O’Neal, who was in foul trouble throughout and finished with just 13 points in 27 minutes.

Silas, who has tried to be supportive during the slide, finally boiled over after the Cavs were outhustled and outrebounded, 55-40, by the Heat.

“When Shaq goes out, you’ve got to get up a killer instinct,” Silas said. “But all I’m seeing right now is, ‘We’re tight, I’m this, I’m that.’ That’s nonsense. We didn’t fight. That’s a loser’s mentality. If we continue to perform as we are, then everything is in danger.”

A few weeks ago, Cleveland’s first trip to the playoffs since 1998 seemed like a slam dunk.

Now it’s a potential air ball.

And Cleveland’s schedule for the rest of March won’t provide many breaks. After entertaining the Magic tonight and the Pacers on Sunday, the Cavaliers have home games against Philadelphia and Detroit and road dates in Milwaukee, Toronto, Houston, Dallas and Chicago.

“We could easily go down the toilet and not make the playoffs,” James said.