What's wrong with the Celtics?

NEW YORK -- I am not a Celtics fan, which put me in the minority Sunday afternoon at Madison Square Garden (where the loudest cheers were for, in order: Kevin Garnett's game-winning shot, Will Ferrell's appearance on the video board, the Knicks' gritty effort).

But all those folks cheering for Boston (there were so many of them they could have nicknamed MSG "The Greenhouse" instead of "The Mecca of Basketball") had to have walked away with as much frustration as enthusiasm after watching the Celtics squeak past the New York Knicks 107-105 in overtime.

The victory was a relief for the Celtics more than a cause for celebration, a win that excused them from having to explain why they've dropped so precipitously (losing three of four before this one) after looking like world-beaters through the first couple of weeks of the season.

We're now 14 games into the season, and there are at least five things that clearly should be of concern to Celtics Nation -- all of which were glaringly obvious Sunday.

Kevin Garnett is still hurting.

Midway through overtime with Boston ahead 105-103, the Celtics ran an out-of-bounds play with one second left on the shot clock on which they threw an alley-oop lob to Garnett at the rim. The play was executed perfectly, but Garnett couldn't get up high enough for the stuff -- something that has happened numerous times this season. On defense, the Knicks repeatedly isolated Al Harrington one-on-one on the perimeter against Garnett, and Harrington repeatedly got around him with ease. The game-winning shot at the end of overtime did get Garnett into double figures in the point column with 10, but he shot 4-for-15 overall.

Rasheed Wallace is playing horribly.

Sheed jacked up six shots Sunday, missing them all, went 0-for-3 from 3-point range and picked up his league-leading fifth technical foul. Coach Doc Rivers yanked him with 7:46 left in the fourth quarter and didn't re-insert him until 9.3 seconds remained in overtime. Wallace has now attempted 128 shots this season, an astounding 81 of which have come from behind the arc. He's shooting 36 percent overall, but just .271 from behind the arc, ranking him 183rd league-wide in 3-point accuracy. Only Trevor Ariza (99), Danny Granger (88), Peja Stojakovic (86), Danilo Gallinari (84) and Channing Frye (83) have attempted more.

• Rajon Rondo's flaws can be quite stark.

For instance, there was the time at the end of regulation, with the score tied at 98, when the Celtics came out of a timeout with 4.7 seconds left with a play drawn up to get the ball into Pierce's hands. But the Knicks blocked Pierce from getting open, and Rondo took the inbounds pass and stood absolutely still for nearly three full seconds before dribbling to the 3-point line and firing up a shot that appeared as though it would have been waved off (for leaving his hand too late) had it gone in. Rondo also made a change to his free throw-shooting routine that he declined to explain afterward, making a pronounced backward jerk with his right shoulder before releasing the ball. It worked on his first two FTs, but he missed four of his next six attempts. His FT percentage for the season is .333 (8-for-24).

• For a team with so many big guys, they sure don't rebound much.

Boston grabbed 11 offensive boards Sunday, which is actually 1.1 more than the Celtics had been averaging coming into this game, when they were ranked 29th, ahead of only the Cleveland Cavaliers. Boston also began the day ranked 24th in second-chance points; another stat that would be getting a lot more attention if the Celtics weren't ranked first in the NBA in field goal percentage and assists. Wallace has grabbed only 11 offensive boards all season, eight fewer than Shelden Williams and nine fewer than Rondo. (And if we take a broader look around, we can include Jon Brockman, Nathan Jawai, Damien Wilkins and Jonas Jerebko among the players with more total offensive rebounds than Wallace.)

Ray Allen is getting no respect.

Never mind that he bricked 5 of 6 3-point attempts, dropping his percentage from behind the arc to 30.3 percent. The refs dissed him even harder late in regulation when, with Boston ahead 98-96 and trying to run down the clock, Allen had the ball in the corner as a double-team came at him. With Wilson Chandler clearly grabbing his jersey to keep Allen from driving around him, Allen was called for an offensive foul. The Knicks then tied the game on the ensuing possession to help send the game to overtime.

• The players aren't listening to Doc Rivers.

OK, this one is a bit of a stretch, but it was true during the Celtics' final timeout of overtime when Rivers drew up a play. "I drew up the play, and Paul [Pierce] came to me and said 'Let's not run that play.' He said 'We were going to run that other play before, let's run [a different play] because if I can get the floor flat, I'm going to get to the basket or Kevin is going to get a shot,'" Rivers said. "Sometimes a coach is a good listener, and that time I was. Honestly, Paul called that. I had a completely different play."

Chris Sheridan covers the NBA for ESPN Insider. To e-mail Sheridan, click here.