They probably won’t cost Boston the seventh seed in the Eastern Conference, but recent struggles on the glass are so bad that they could contribute to an early playoff exit. If the Celtics continue to rebound like they have during this five game losing streak, it won’t matter if Kevin Garnett is healthy or who they play in the first round.

Last night at TD Garden, Carmelo Anthony and J.R. Smith hesitated to shoot even less than usual. They pushed their way inside and took contested, driving shots. Smith, typically a hot-cold shooter who needs to mix in outside shots to light up a defense, took just three shots from beyond the arc and still scored 32 points. He didn’t have to set up drives with defense-extending threes, partially because second-chance point opportunities were so available.

Anthony, too big and too strong for the Celtics small lineup, was able to secure his own misses. He finished with 29. The Knicks tallied 15 offensive boards without Tyson Chandler and Amar’e Stoudemire, more than doubling the Celtics efforts.

It’s no secret that the Celtics, now 36-34, have been a poor rebounding team all year – they are one of only two NBA teams averaging under 40 rebounds per game. The other is the Miami Heat, but coach Erik Spoelstra is probably okay with that right now. Miami has proven 27 straight times that it doesn’t need to outrebound its opponents to win games.

Still, the Heat bested Boston on the boards last Monday anyway. The team pulling down the fewest in the league managed to outrebound the Celtics 39-33 and grab 10 on the offensive end. That was the first of five straight losses for the Celtics, who have shot a better percentage than their opponent in all but one of those games and still lost them all.

The real difference is how many offensive rebounds Boston is giving up. This season Doc Rivers has a slightly above average defensive rebounding team (12^th in defensive rebounds per game). The team usually neglects the offensive glass (29^th in offensive rebounds), but on this losing streak the Celtics are surrendering almost two more offensive rebounds per game than they have all season. They have often been more efficient scorers, which was a problem earlier in the year. Now Boston just doesn’t get as many chances to score as its opponents. Allowing offensive rebounds has wasted great offensive performances from the team and from its players.

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Missing Garnett last night certainly had something to do with the rebounding trouble. Garnett sat out his second straight game and is expected to miss a couple weeks with an inflamed left ankle. He is an intimidating rim protector, but even with him the Celtics struggled to rebound in their last five games. They managed only 28 total rebounds in New Orleans last week, 11 below their already sub-par season average. The Hornets punished the Celtics with 17 more rebounds, seven of them offensive. The last one, a tip-in from rookie Anthony Davis, decided the game.

There’s a semblance of a silver lining here, though, at least before the playoffs. It’s the Celtics remaining schedule. Only two of their twelve remaining opponents are in the top ten in total rebounding. The Celtics get both of those teams at home, where they looked feeble last night but are still 24-11 this season. Behind a difficult March looms a more favorable April schedule. Seven of their final twelve games are against squads outside the playoff picture. Maybe Boston can work out the rebounding kinks against softer competition before the playoffs.

The Milwaukee Bucks (34-35) are just a game and a half back of the Celtics for the seventh playoff spot, but they are in a tailspin of their own. Just 2-6 in their last eight games, no opponent has scored less than 98 points against Milwaukee this month. In April the Bucks travel to New York, Miami, Atlanta and Oklahoma City. They’ll have to play their best basketball to win even one of those games.

Boston is seven and a half games back of the division-leading Knicks, almost assuring that the team will miss out on a division crown for the first time in five years. But the Celtics could get a chance to avenge the title, and last night’s loss, in the playoffs. If New York holds on to the second seed they’ll match up with Boston in the first round. The Celtics are 1-2 in the season series, and the teams meet again this Sunday in Madison Square Garden.

The Pacers might eclipse the Knicks for the second seed. The good news if that happens? The Celtics are 2-0 against them this season. The bad news? Indiana is the best total rebounding team in the league. Pick your poison, Celtics fans. Hopefully Garnett will be back for the playoffs, but the Celtics look beyond the help of one man on the glass. If only Jared Sullinger were healthy.